rxdb/ERROR-MESSAGES.md

A local-first realtime NoSQL Database for JavaScript applications - https://rxdb.info/

# RxDB Error Messages

This file is generated automatically. Do not edit it manually.

## undefined

**Message**: `given name is no string or empty`

**Cause**: The database name must be a non-empty string.

**Fix**: Check the name used when creating the database.

---

## undefined

**Message**: `collection- and database-names must match the regex to be compatible with couchdb databases.
    See https://neighbourhood.ie/blog/2020/10/13/everything-you-need-to-know-about-couchdb-database-names/
    info: if your database-name specifies a folder, the name must contain the slash-char '/' or '\'`

**Cause**: The database name does not match the regex required for CouchDB compatibility.

**Fix**: Change the database name to match the regex: ^[a-z][_$a-zA-Z0-9\-]*$

---

## undefined

**Message**: `replication-direction must either be push or pull or both. But not none`

**Cause**: Replication must have at least one direction (push or pull) enabled.

**Fix**: Set push or pull to true or provide options for them.

**Docs**: https://rxdb.info/replication.html?console=errors&code=UT3

---

## undefined

**Message**: `given leveldown is no valid adapter`

---

## undefined

**Message**: `keyCompression is set to true in the schema but no key-compression handler is used in the storage`

**Cause**: Key compression is not supported by this RxStorage adapter or you forgot to add the key-compression plugin.

**Fix**: Disable key compression in the schema or add the proper plugin.

---

## undefined

**Message**: `schema contains encrypted fields but no encryption handler is used in the storage`

**Cause**: Encryption is not supported by this RxStorage adapter or you forgot to add the encryption plugin.

**Fix**: Disable encryption in the schema or add the proper plugin.

**Docs**: https://rxdb.info/encryption.html?console=errors&code=UT6

---

## undefined

**Message**: `attachments.compression is enabled but no attachment-compression plugin is used`

**Cause**: Attachment compression is not supported by this RxStorage adapter or you forgot to add the attachment-compression plugin.

**Fix**: Disable attachment compression in the schema or add the proper plugin.

---

## undefined

**Message**: `crypto.subtle.digest is not available in your runtime. For expo/react-native you need to polyfill those, see https://github.com/pubkey/rxdb/blob/master/examples/react-native/initializeDb.js#L24 `

**Cause**: The Web Crypto API is not available in this environment.

**Fix**: Use a polyfill or an environment that supports the Web Crypto API, or provide a custom hash function.

**Docs**: https://rxdb.info/rx-database.html?console=errors&code=UT8#ignoreduplicate

---

## undefined

**Message**: `Given plugin is not RxDB plugin.`

**Cause**: The added plugin is not a valid RxDB plugin object.

**Fix**: Ensure you are adding a valid RxDB plugin object.

**Docs**: https://rxdb.info/plugins.html?console=errors&code=PL1

---

## undefined

**Message**: `A plugin with the same name was already added but it was not the exact same JavaScript object`

**Cause**: A plugin with the same name has already been added.

**Fix**: Check if you are adding the same plugin twice or if you have multiple versions of the same plugin.

**Docs**: https://rxdb.info/plugins.html?console=errors&code=PL3

---

## undefined

**Message**: `bulkWrite() cannot be called with an empty array`

**Cause**: bulkWrite was called with an empty array of documents.

**Fix**: Ensure the array passed to bulkWrite is not empty.

---

## undefined

**Message**: `RxQuery._execOverDatabase(): op not known`

**Cause**: Unknown RxQuery operation.

**Fix**: This is likely an internal error. Contact the maintainer.

---

## undefined

**Message**: `RxQuery.regex(): You cannot use .regex() on the primary field`

**Cause**: This is not supported by the query engine.

**Fix**: Use a different field or a primary key lookup.

**Docs**: https://rxdb.info/rx-query.html?console=errors&code=QU4

---

## undefined

**Message**: `RxQuery.sort(): does not work because key is not defined in the schema`

**Cause**: The field used for sorting is not defined in the schema.

**Fix**: Add the field to the schema or sort by a different field.

**Docs**: https://rxdb.info/rx-query.html?console=errors&code=QU5#sort

---

## undefined

**Message**: `RxQuery.limit(): cannot be called on .findOne()`

**Cause**: findOne queries cannot have a limit.

**Fix**: Remove the limit from the query or use find() instead.

**Docs**: https://rxdb.info/rx-query.html?console=errors&code=QU6

---

## undefined

**Message**: `throwIfMissing can only be used in findOne queries`

**Cause**: throwIfMissing was used on a find query.

**Fix**: Use findOne if you want to use throwIfMissing or remove the flag.

---

## undefined

**Message**: `result empty and throwIfMissing: true`

**Cause**: exec(true) or remove(true) was called on a findOne() query but the document was not found.

**Fix**: Ensure the document exists or do not use the throwIfMissing flag.

---

## undefined

**Message**: `RxQuery: no valid query params given`

**Cause**: The query object is not a valid Mango query or contains invalid keys.

**Fix**: Ensure the query object is a valid Mango query.

**Docs**: https://rxdb.info/rx-query.html?console=errors&code=QU11

---

## undefined

**Message**: `Given index is not in schema`

**Cause**: The index used in the query is not defined in the schema.

**Fix**: Add the index to the schema or use a different index.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=QU12#indexes

---

## undefined

**Message**: `A top level field of the query is not included in the schema`

**Cause**: A field used in the query is not defined in the schema.

**Fix**: Ensure all fields in the query are defined in the schema.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=QU13

---

## undefined

**Message**: `Running a count() query in slow mode is now allowed. Either run a count() query with a selector that fully matches an index or set allowSlowCount=true when calling the createRxDatabase`

**Cause**: A count query is running without an index, which is slow.

**Fix**: Add an index for the query or allow slow count queries.

**Docs**: https://rxdb.info/rx-collection.html?console=errors&code=QU14#count

---

## undefined

**Message**: `For count queries it is not allowed to use skip or limit`

**Cause**: Count queries cannot have a limit or skip.

**Fix**: Remove limit and skip from the count query.

---

## undefined

**Message**: `$regex queries must be defined by a string, not an RegExp instance. This is because RegExp objects cannot be JSON stringified and also they are mutable which would be dangerous`

**Cause**: RegExp objects are not allowed in queries.

**Fix**: Use string based regex operators instead.

**Docs**: https://rxdb.info/rx-query.html?console=errors&code=QU16#regex

---

## undefined

**Message**: `Chained queries cannot be used on findByIds() RxQuery instances`

**Cause**: Query builder methods cannot be used with findByIds.

**Fix**: Use find() if you want to use the query builder.

---

## undefined

**Message**: `Malformed query result data. This likely happens because you create a OPFS-storage RxDatabase inside of a worker but did not set the usesRxDatabaseInWorker setting. https://rxdb.info/rx-storage-opfs.html?console=opfs#setting-usesrxdatabaseinworker-when-a-rxdatabase-is-also-used-inside-of-the-worker `

**Cause**: The result data for the query is undefined or malformed.

**Fix**: Check if you are using OPFS in a worker correctly.

**Docs**: https://rxdb.info/rx-storage-opfs.html?console=errors&code=QU18#setting-usesrxdatabaseinworker-when-a-rxdatabase-is-also-used-inside-of-the-worker

---

## undefined

**Message**: `Queries must not contain fields or properties with the value `undefined`: https://github.com/pubkey/rxdb/issues/6792#issuecomment-2624555824 `

**Cause**: A field in the query is undefined.

**Fix**: Ensure all fields in the query have valid values.

**Docs**: https://github.com/pubkey/rxdb/issues/6792?console=errors&code=QU19#issuecomment-2624555824

---

## undefined

**Message**: `path must be a string or object`

---

## undefined

**Message**: `Invalid argument`

---

## undefined

**Message**: `Invalid sort() argument. Must be a string, object, or array`

---

## undefined

**Message**: `Invalid argument. Expected instanceof mquery or plain object`

---

## undefined

**Message**: `method must be used after where() when called with these arguments`

---

## undefined

**Message**: `Can't mix sort syntaxes. Use either array or object | .sort([['field', 1], ['test', -1]]) | .sort({ field: 1, test: -1 })`

---

## undefined

**Message**: `Invalid sort value`

---

## undefined

**Message**: `Can't mix sort syntaxes. Use either array or object`

---

## undefined

**Message**: `RxDocument.prepare(): another instance on this adapter has a different password`

**Cause**: You tried to create a secondary instance on an adapter that is already used by another instance with a different password.

**Fix**: Ensure that all instances use the same password.

**Docs**: https://rxdb.info/encryption.html?console=errors&code=DB1

---

## undefined

**Message**: `RxDatabase.addCollections(): collection-names cannot start with underscore _`

**Cause**: You tried to create a collection where the name starts with an underscore.

**Fix**: Change the collection name so it does not start with an underscore.

**Docs**: https://rxdb.info/rx-collection.html?console=errors&code=DB2

---

## undefined

**Message**: `RxDatabase.addCollections(): collection already exists. use myDatabase[collectionName] to get it`

**Cause**: You tried to add a collection that already exists on this database instance.

**Fix**: Use the existing collection or use a different name.

**Docs**: https://rxdb.info/rx-collection.html?console=errors&code=DB3

---

## undefined

**Message**: `RxDatabase.addCollections(): schema is missing`

**Cause**: You called addCollections() but did not provide a schema for the collection.

**Fix**: Provide a valid schema for the collection.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=DB4

---

## undefined

**Message**: `RxDatabase.addCollections(): collection-name not allowed`

**Cause**: You used a collection name that contains invalid characters.

**Fix**: Use only allowed characters (a-z, A-Z, 0-9, -, _).

**Docs**: https://rxdb.info/rx-collection.html?console=errors&code=DB5

---

## undefined

**Message**: `RxDatabase.addCollections(): another instance created this collection with a different schema. Read thishttps://rxdb.info/rx-schema.html?console=qa#faq `

**Cause**: The schema hash does not match the schema stored in the internal database.

**Fix**: If you changed the schema, you must increment the version number. If not, check why the hash is different.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=DB6#faq

---

## undefined

**Message**: `createRxDatabase(): A RxDatabase with the same name and adapter already exists.
Make sure to use this combination of storage+databaseName only once
If you have the duplicate database on purpose to simulate multi-tab behavior in unit tests, set "ignoreDuplicate: true".
As alternative you can set "closeDuplicates: true" like if this happens in your react projects with hot reload that reloads the code without reloading the process.`

**Cause**: You created multiple RxDatabase instances with the same name and adapter.

**Fix**: Ensure that you only create one instance of the database.

**Docs**: https://rxdb.info/rx-database.html?console=errors&code=DB8

---

## undefined

**Message**: `ignoreDuplicate is only allowed in dev-mode and must never be used in production`

**Cause**: You used the ignoreDuplicate option in a production environment.

**Fix**: Remove ignoreDuplicate: true or switch to dev-mode.

**Docs**: https://rxdb.info/rx-database.html?console=errors&code=DB9

---

## undefined

**Message**: `createRxDatabase(): Invalid db-name, folder-paths must not have an ending slash`

**Cause**: The database name or path has a trailing slash.

**Fix**: Remove the trailing slash from the name/path.

**Docs**: https://rxdb.info/rx-database.html?console=errors&code=DB11

---

## undefined

**Message**: `RxDatabase.addCollections(): could not write to internal store`

**Cause**: Writing to the internal storage failed.

**Fix**: Check your storage configuration and permissions.

**Docs**: https://rxdb.info/rx-storage.html?console=errors&code=DB12

---

## undefined

**Message**: `createRxDatabase(): Invalid db-name or collection name, name contains the dollar sign`

**Cause**: The name contains a dollar sign which is not allowed.

**Fix**: Remove the dollar sign from the name.

**Docs**: https://rxdb.info/rx-database.html?console=errors&code=DB13

---

## undefined

**Message**: `no custom reactivity factory added on database creation`

**Cause**: You tried to use reactivity but no factory was provided.

**Fix**: Add a reactivity factory (e.g. for React, Vue, Angular) or use a plugin that adds one.

**Docs**: https://rxdb.info/reactivity.html?console=errors&code=DB14

---

## undefined

**Message**: `RxDocument.insert() You cannot insert an existing document`

**Cause**: You tried to insert a document with a primary key that already exists.

**Fix**: Use upsert() if you want to overwrite.

**Docs**: https://rxdb.info/rx-collection.html?console=errors&code=COL1#insert

---

## undefined

**Message**: `RxCollection.insert() fieldName ._id can only be used as primaryKey`

**Cause**: You have a field named "_id" but it is not defined as the primary key.

**Fix**: Rename the field or use it as the primary key.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=COL2

---

## undefined

**Message**: `RxCollection.upsert() does not work without primary`

**Cause**: You called upsert() but the document data does not contain the primary key.

**Fix**: Ensure the primary key is present in the document data.

**Docs**: https://rxdb.info/rx-collection.html?console=errors&code=COL3#upsert

---

## undefined

**Message**: `RxCollection.incrementalUpsert() does not work without primary`

**Cause**: You called incrementalUpsert() but the document data does not contain the primary key.

**Fix**: Ensure the primary key is present in the document data.

**Docs**: https://rxdb.info/rx-collection.html?console=errors&code=COL4#incrementalupsert

---

## undefined

**Message**: `RxCollection.find() if you want to search by _id, use .findOne(_id)`

**Cause**: You called find() with a string argument, which was supported in older versions.

**Fix**: Use findOne(id) to find a single document by ID.

**Docs**: https://rxdb.info/rx-collection.html?console=errors&code=COL5#find

---

## undefined

**Message**: `RxCollection.findOne() needs a queryObject or string. Notice that in RxDB, primary keys must be strings and cannot be numbers.`

**Cause**: You called findOne() with an invalid argument (likely a number or array).

**Fix**: Use a string ID or a mongo-style query object.

**Docs**: https://rxdb.info/rx-collection.html?console=errors&code=COL6#findone

---

## undefined

**Message**: `hook must be a function`

**Cause**: You provided a hook that is not a function.

**Fix**: Ensure the hook is a function.

**Docs**: https://rxdb.info/middleware.html?console=errors&code=COL7

---

## undefined

**Message**: `hooks-when not known`

**Cause**: You provided a hook with an invalid "when" parameter (must be "pre" or "post").

**Fix**: Use "pre" or "post" as the "when" parameter.

**Docs**: https://rxdb.info/middleware.html?console=errors&code=COL8

---

## undefined

**Message**: `RxCollection.addHook() hook-name not known`

**Cause**: You provided a hook name that is not known (e.g. insert, save, remove).

**Fix**: Use a valid hook name.

**Docs**: https://rxdb.info/middleware.html?console=errors&code=COL9

---

## undefined

**Message**: `RxCollection .postCreate-hooks cannot be async`

**Cause**: You defined a postCreate hook as async, which is not allowed.

**Fix**: Make the postCreate hook synchronous.

**Docs**: https://rxdb.info/middleware.html?console=errors&code=COL10

---

## undefined

**Message**: `migrationStrategies must be an object`

**Cause**: You provided migration strategies that are not an object.

**Fix**: Provide an object mapping versions to migration functions.

**Docs**: https://rxdb.info/migration-schema.html?console=errors&code=COL11

---

## undefined

**Message**: `A migrationStrategy is missing or too much`

**Cause**: The number of migration strategies does not match the schema version difference.

**Fix**: Ensure you have a migration strategy for every version step.

**Docs**: https://rxdb.info/migration-schema.html?console=errors&code=COL12

---

## undefined

**Message**: `migrationStrategy must be a function`

**Cause**: One of your migration strategies is not a function.

**Fix**: Ensure all migration strategies are functions.

**Docs**: https://rxdb.info/migration-schema.html?console=errors&code=COL13

---

## undefined

**Message**: `given static method-name is not a string`

**Cause**: The name of a static method is not a string.

**Fix**: Provide a string as the method name.

**Docs**: https://rxdb.info/orm.html?console=errors&code=COL14

---

## undefined

**Message**: `static method-names cannot start with underscore _`

**Cause**: You tried to define a static method starting with an underscore.

**Fix**: Rename the method.

**Docs**: https://rxdb.info/orm.html?console=errors&code=COL15

---

## undefined

**Message**: `given static method is not a function`

**Cause**: You provided a static method that is not a function.

**Fix**: Ensure the static method is a function.

**Docs**: https://rxdb.info/orm.html?console=errors&code=COL16

---

## undefined

**Message**: `RxCollection.ORM: statics-name not allowed`

**Cause**: You used a reserved name for a static method.

**Fix**: Choose a different name for the static method.

**Docs**: https://rxdb.info/orm.html?console=errors&code=COL17

---

## undefined

**Message**: `collection-method not allowed because fieldname is in the schema`

**Cause**: You tried to define a collection method that conflicts with a schema field.

**Fix**: Rename the collection method or the schema field.

**Docs**: https://rxdb.info/orm.html?console=errors&code=COL18

---

## undefined

**Message**: `Storage write error`

**Cause**: The storage engine returned an error when writing data.

**Fix**: Check the error details.

**Docs**: https://rxdb.info/rx-storage.html?console=errors&code=COL20

---

## undefined

**Message**: `The RxCollection is closed or removed already, either from this JavaScript realm or from another, like a browser tab`

**Cause**: You tried to access a collection that has been closed or removed.

**Fix**: Ensure the collection is open before accessing it.

---

## undefined

**Message**: `WebMCP Agent attempted to delete a document that does not exist`

**Cause**: The explicitly requested ID for deletion could not be found in the database.

**Fix**: Ensure the agent queries for the document correctly before trying to delete it.

---

## undefined

**Message**: `Document update conflict. When changing a document you must work on the previous revision`

**Cause**: You tried to update a document but the revision you provided is not the latest one.

**Fix**: Fetch the latest document revision and apply your changes again.

**Docs**: https://rxdb.info/transactions-conflicts-revisions.html?console=errors&code=CONFLICT

---

## undefined

**Message**: `.bulkInsert() and .bulkUpsert() cannot be run with multiple documents that have the same primary key. Conflicting primary key(s) are in the error parameters (duplicateIds)`

**Cause**: You provided multiple documents with the same primary key in a bulk write.

**Fix**: Ensure all documents in a bulk write have unique primary keys.

---

## undefined

**Message**: `In the open-source version of RxDB, the amount of collections that can exist in parallel is limited to 16. If you already purchased the premium access, you can remove this limit: https://rxdb.info/rx-collection.html?console=limit#faq`

**Cause**: You have reached the limit of open collections for the free version.

**Fix**: Reduce the number of open collections or upgrade to premium.

**Docs**: https://rxdb.info/premium.html?console=errors&code=COL23

---

## undefined

**Message**: `inline _attachments must be an array of { id, type, data } objects; the map format is reserved for internal use only`

**Cause**: An object was passed as _attachments that is neither an array of attachment creators nor a fully-normalized internal map.

**Fix**: Pass attachments as an array: [{ id, type, data }]. This is the same format used by putAttachment().

**Docs**: https://rxdb.info/rx-attachment.html?console=errors&code=COL24

---

## undefined

**Message**: `RxDocument.get$ cannot get observable of in-array fields because order cannot be guessed`

**Cause**: You tried to observe an array item, which is not supported.

**Fix**: Observe the array field itself.

---

## undefined

**Message**: `cannot observe primary path`

**Cause**: You tried to observe the primary key, which is immutable.

**Fix**: Observe the document itself or use findOne().

---

## undefined

**Message**: `final fields cannot be observed`

**Cause**: You tried to observe a final field, which is immutable.

**Fix**: Observe the document itself.

---

## undefined

**Message**: `RxDocument.get$ cannot observe a non-existed field`

**Cause**: The field you tried to observe is not defined in the schema.

**Fix**: Check the field name and schema definition.

---

## undefined

**Message**: `RxDocument.populate() cannot populate a non-existed field`

**Cause**: The field you tried to populate is not defined in the schema.

**Fix**: Check the field name and schema definition.

**Docs**: https://rxdb.info/population.html?console=errors&code=DOC5

---

## undefined

**Message**: `RxDocument.populate() cannot populate because path has no ref`

**Cause**: The field you tried to populate does not have a "ref" property in the schema.

**Fix**: Add the "ref" property to the field schema.

**Docs**: https://rxdb.info/population.html?console=errors&code=DOC6

---

## undefined

**Message**: `RxDocument.populate() ref-collection not in database`

**Cause**: The collection referenced in the schema does not exist.

**Fix**: Create the referenced collection.

**Docs**: https://rxdb.info/population.html?console=errors&code=DOC7

---

## undefined

**Message**: `RxDocument.set(): primary-key cannot be modified`

**Cause**: You tried to modify the primary key of a document.

**Fix**: Primary keys are immutable. Create a new document with the new ID instead.

---

## undefined

**Message**: `final fields cannot be modified`

**Cause**: You tried to modify a field marked as final in the schema.

**Fix**: Final fields are immutable.

---

## undefined

**Message**: `RxDocument.set(): cannot set childpath when rootPath not selected`

**Cause**: You tried to set a nested field without having the root path in the document data.

**Fix**: Ensure the root path exists before setting nested fields.

---

## undefined

**Message**: `RxDocument.save(): can't save deleted document`

**Cause**: You tried to save a document that has already been deleted.

**Fix**: Do not save deleted documents. Insert them again if you want to recreate them.

---

## undefined

**Message**: `RxDocument.remove(): Document is already deleted`

**Cause**: You tried to remove a document that is already deleted.

**Fix**: Check if the document is deleted before removing it.

---

## undefined

**Message**: `RxDocument.close() does not exist`

**Cause**: You called close() on a RxDocument, which is not supported.

**Fix**: Documents do not need to be closed.

---

## undefined

**Message**: `query cannot be an array`

**Cause**: You provided an array as a query, which is not valid.

**Fix**: Provide a valid query object.

---

## undefined

**Message**: `Since version 8.0.0 RxDocument.set() can only be called on temporary RxDocuments`

**Cause**: You called set() on a non-temporary document.

**Fix**: Use update(), patch() or modify() to change document data.

**Docs**: https://rxdb.info/rx-document.html?console=errors&code=DOC16#update

---

## undefined

**Message**: `Since version 8.0.0 RxDocument.save() can only be called on non-temporary documents`

**Cause**: You called save() on a temporary document.

**Fix**: Use another method to save the document or ensure it is not temporary.

**Docs**: https://rxdb.info/rx-document.html?console=errors&code=DOC17#save

---

## undefined

**Message**: `Document property for composed primary key is missing`

**Cause**: A field required for the composite primary key is missing in the document data.

**Fix**: Ensure all fields of the composite primary key are set.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=DOC18#composite-primary-key

---

## undefined

**Message**: `Value of primary key(s) cannot be changed`

**Cause**: You tried to modify the primary key of a document.

**Fix**: Primary keys are immutable. Create a new document with the new ID instead.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=DOC19#primary-key

---

## undefined

**Message**: `PrimaryKey missing`

**Cause**: The document data is missing a primary key.

**Fix**: Ensure the document has a primary key.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=DOC20#primary-key

---

## undefined

**Message**: `PrimaryKey must be equal to PrimaryKey.trim(). It cannot start or end with a whitespace`

**Cause**: The primary key contains leading or trailing whitespace.

**Fix**: Trim the primary key.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=DOC21#primary-key

---

## undefined

**Message**: `PrimaryKey must not contain a linebreak`

**Cause**: The primary key contains newline characters.

**Fix**: Remove newline characters from the primary key.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=DOC22#primary-key

---

## undefined

**Message**: `PrimaryKey must not contain a double-quote ["]`

**Cause**: The primary key contains double quotes.

**Fix**: Remove double quotes from the primary key.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=DOC23#primary-key

---

## undefined

**Message**: `Given document data could not be structured cloned. This happens if you pass non-plain-json data into it, like a Date() object or a Function. In vue.js this happens if you use ref() on the document data which transforms it into a Proxy object.`

**Cause**: The document data contains objects that cannot be structured-cloned (e.g. Date, RegExp).

**Fix**: Use only JSON-serializable data. Store dates as strings.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=DOC24

---

## undefined

**Message**: `migrate() Migration has already run`

**Cause**: You tried to run the migration manually but it has already been finished.

**Fix**: Check if the migration is already done.

**Docs**: https://rxdb.info/migration-schema.html?console=errors&code=DM1

---

## undefined

**Message**: `migration of document failed final document does not match final schema`

**Cause**: The migration strategy produced a document that does not match the new schema.

**Fix**: Check your migration strategy and the new schema.

**Docs**: https://rxdb.info/migration-schema.html?console=errors&code=DM2

---

## undefined

**Message**: `migration already running`

**Cause**: You started the migration while another migration is already running.

**Fix**: Await the running migration.

**Docs**: https://rxdb.info/migration-schema.html?console=errors&code=DM3

---

## undefined

**Message**: `Migration errored`

**Cause**: An error occurred during migration.

**Fix**: Check the error details.

**Docs**: https://rxdb.info/migration-schema.html?console=errors&code=DM4

---

## undefined

**Message**: `Cannot open database state with newer RxDB version. You have to migrate your database state first. See https://rxdb.info/migration-storage.html?console=storage `

**Cause**: The database was created with an older RxDB version and needs migration.

**Fix**: Run the storage migration.

**Docs**: https://rxdb.info/migration-storage.html?console=errors&code=DM5

---

## undefined

**Message**: `to use attachments, please define this in your schema`

**Cause**: You tried to use attachments but they are not enabled in the schema.

**Fix**: Enable attachments in the schema.

**Docs**: https://rxdb.info/rx-attachment.html?console=errors&code=AT1

---

## undefined

**Message**: `inline attachment must have id and type (strings) and data (Blob)`

**Cause**: An inline attachment object is missing a required field or data is not a Blob instance.

**Fix**: Ensure each inline attachment has { id: string, type: string, data: Blob }.

**Docs**: https://rxdb.info/rx-attachment.html?console=errors&code=AT2

---

## undefined

**Message**: `duplicate attachment id`

**Cause**: The same attachment id appears multiple times in the inline attachments array.

**Fix**: Ensure each attachment id is unique in the array.

**Docs**: https://rxdb.info/rx-attachment.html?console=errors&code=AT3

---

## undefined

**Message**: `_attachments missing on document`

**Cause**: A document is missing the _attachments property during an attachments write operation.

**Fix**: Ensure documents have the _attachments property set.

**Docs**: https://rxdb.info/rx-attachment.html?console=errors&code=AT4

---

## undefined

**Message**: `password is not valid`

**Cause**: The password provided is invalid (must be a string).

**Fix**: Provide a valid string password.

**Docs**: https://rxdb.info/encryption.html?console=errors&code=EN1

---

## undefined

**Message**: `validatePassword: min-length of password not complied`

**Cause**: The password is too short.

**Fix**: Use a longer password (min 12 chars).

**Docs**: https://rxdb.info/encryption.html?console=errors&code=EN2

---

## undefined

**Message**: `Schema contains encrypted properties but no password is given`

**Cause**: Encryption enabled in schema but no password provided.

**Fix**: Provide a password.

**Docs**: https://rxdb.info/encryption.html?console=errors&code=EN3

---

## undefined

**Message**: `Password not valid`

**Cause**: The password provided is invalid.

**Fix**: Check the password.

**Docs**: https://rxdb.info/encryption.html?console=errors&code=EN4

---

## undefined

**Message**: `Storage wrapper received a string instead of an array from the storage. This happens when a storage like OPFS is used inside of a worker and the usesRxDatabaseInWorker option is not set.`

**Cause**: Some RxStorage implementations (like OPFS) return JSON strings instead of arrays for performance. When you wrap such a storage with encryption (or other plugins) inside of a worker, the wrapper receives the raw string and cannot process it.

**Fix**: Set usesRxDatabaseInWorker: true in your storage options. For example: getRxStorageOPFS({ usesRxDatabaseInWorker: true }).

**Docs**: https://rxdb.info/encryption.html?console=errors&code=EN5

---

## undefined

**Message**: `You must create the collections before you can import their data`

**Cause**: Importing data into a non-existent collection.

**Fix**: Create the collection before importing.

**Docs**: https://rxdb.info/backup.html?console=errors&code=JD1

---

## undefined

**Message**: `RxCollection.importJSON(): the imported json relies on a different schema`

**Cause**: The imported data schema does not match the collection schema.

**Fix**: Ensure schemas match.

**Docs**: https://rxdb.info/backup.html?console=errors&code=JD2

---

## undefined

**Message**: `RxCollection.importJSON(): json.passwordHash does not match the own`

**Cause**: Password mismatch in import.

**Fix**: Use the same password.

**Docs**: https://rxdb.info/backup.html?console=errors&code=JD3

---

## undefined

**Message**: `RxDocument.allAttachments$ can't use attachments on local documents`

**Cause**: You tried to use attachments on a local document, which is not supported.

**Fix**: Do not use attachments with local documents.

**Docs**: https://rxdb.info/rx-local-document.html?console=errors&code=LD1

---

## undefined

**Message**: `RxDocument.get(): objPath must be a string`

**Cause**: The object path provided to get() is not a string.

**Fix**: Provide a valid string path.

**Docs**: https://rxdb.info/rx-local-document.html?console=errors&code=LD2

---

## undefined

**Message**: `RxDocument.get$ cannot get observable of in-array fields because order cannot be guessed`

**Cause**: You tried to observe an array item in a local document.

**Fix**: Observe the whole array instead.

**Docs**: https://rxdb.info/rx-local-document.html?console=errors&code=LD3

---

## undefined

**Message**: `cannot observe primary path`

**Cause**: You tried to observe the primary path of a local document.

**Fix**: Observe the document data instead.

**Docs**: https://rxdb.info/rx-local-document.html?console=errors&code=LD4

---

## undefined

**Message**: `RxDocument.set() id cannot be modified`

**Cause**: You tried to modify the ID of a local document.

**Fix**: IDs are immutable. Create a new document if needed.

**Docs**: https://rxdb.info/rx-local-document.html?console=errors&code=LD5

---

## undefined

**Message**: `LocalDocument: Function is not usable on local documents`

**Cause**: You called a function that is not supported on local documents.

**Fix**: Check the documentation for supported methods.

**Docs**: https://rxdb.info/rx-local-document.html?console=errors&code=LD6

---

## undefined

**Message**: `Local document already exists`

**Cause**: You tried to create a local document that already exists.

**Fix**: Use upsert() or update the existing document.

**Docs**: https://rxdb.info/rx-local-document.html?console=errors&code=LD7

---

## undefined

**Message**: `localDocuments not activated. Set localDocuments=true on creation, when you want to store local documents on the RxDatabase or RxCollection.`

**Cause**: You tried to use local documents but they are not enabled.

**Fix**: Enable local documents when creating the database or collection.

**Docs**: https://rxdb.info/rx-local-document.html?console=errors&code=LD8

---

## undefined

**Message**: `Replication: already added`

**Cause**: You started a replication that is already running.

**Fix**: Check if the replication is already running before starting it.

**Docs**: https://rxdb.info/replication.html?console=errors&code=RC1

---

## undefined

**Message**: `replicateCouchDB() query must be from the same RxCollection`

**Cause**: You used a query from a different collection for replication.

**Fix**: Use a query from the same collection.

**Docs**: https://rxdb.info/replication-couchdb.html?console=errors&code=RC2

---

## undefined

**Message**: `RxCouchDBReplicationState.awaitInitialReplication() cannot await initial replication when live: true`

**Cause**: You tried to await initial replication on a live replication.

**Fix**: Set live: false if you want to await initial replication.

**Docs**: https://rxdb.info/replication-couchdb.html?console=errors&code=RC4

---

## undefined

**Message**: `RxCouchDBReplicationState.awaitInitialReplication() cannot await initial replication if multiInstance because the replication might run on another instance`

**Cause**: You tried to await initial replication in a multi-instance environment.

**Fix**: Await initial replication only in single-instance mode.

**Docs**: https://rxdb.info/replication-couchdb.html?console=errors&code=RC5

---

## undefined

**Message**: `syncFirestore() serverTimestampField MUST NOT be part of the collections schema and MUST NOT be nested.`

**Cause**: The serverTimestampField is defined in the schema or is nested.

**Fix**: Remove the serverTimestampField from the schema and ensure it is at the top level.

**Docs**: https://rxdb.info/replication-firestore.html?console=errors&code=RC6

---

## undefined

**Message**: `SimplePeer requires to have process.nextTick() polyfilled, see https://rxdb.info/replication-webrtc.html?console=webrtc `

**Cause**: process.nextTick is missing in the runtime environment.

**Fix**: Polyfill process.nextTick.

**Docs**: https://rxdb.info/replication-webrtc.html?console=errors&code=RC7

---

## undefined

**Message**: `RxReplication pull handler threw an error - see .errors for more details`

**Cause**: The pull handler of the replication threw an error.

**Fix**: Check the error details in the .errors observable.

**Docs**: https://rxdb.info/replication.html?console=errors&code=RC_PULL

---

## undefined

**Message**: `RxReplication pull stream$ threw an error - see .errors for more details`

**Cause**: The pull stream of the replication threw an error.

**Fix**: Check the error details in the .errors observable.

**Docs**: https://rxdb.info/replication.html?console=errors&code=RC_STREAM

---

## undefined

**Message**: `RxReplication push handler threw an error - see .errors for more details`

**Cause**: The push handler of the replication threw an error.

**Fix**: Check the error details in the .errors observable.

**Docs**: https://rxdb.info/replication.html?console=errors&code=RC_PUSH

---

## undefined

**Message**: `RxReplication push handler did not return an array with the conflicts`

**Cause**: The push handler returned a non-array value.

**Fix**: Ensure the push handler returns an array of conflicting documents.

**Docs**: https://rxdb.info/replication.html?console=errors&code=RC_PUSH_NO_AR

---

## undefined

**Message**: `RxReplication WebRTC Peer has error`

**Cause**: A WebRTC peer connection error occurred.

**Fix**: Check the network connection and WebRTC configuration.

**Docs**: https://rxdb.info/replication-webrtc.html?console=errors&code=RC_WEBRTC_PEER

---

## undefined

**Message**: `replicateCouchDB() url must end with a slash like 'https://example.com/mydatabase/'`

**Cause**: The CouchDB URL is missing a trailing slash.

**Fix**: Add a trailing slash to the URL.

**Docs**: https://rxdb.info/replication-couchdb.html?console=errors&code=RC_COUCHDB_1

---

## undefined

**Message**: `replicateCouchDB() did not get valid result with rows.`

**Cause**: The CouchDB endpoint returned an invalid response.

**Fix**: Check the CouchDB server and the URL.

**Docs**: https://rxdb.info/replication-couchdb.html?console=errors&code=RC_COUCHDB_2

---

## undefined

**Message**: `Outdated client, update required. Replication was canceled`

**Cause**: The client version is too old for the server.

**Fix**: Update the client application.

**Docs**: https://rxdb.info/replication.html?console=errors&code=RC_OUTDATED

---

## undefined

**Message**: `Unauthorized client, update the replicationState.headers to set correct auth data`

**Cause**: The client is not authorized to replicate.

**Fix**: Update authentication headers.

**Docs**: https://rxdb.info/replication.html?console=errors&code=RC_UNAUTHORIZED

---

## undefined

**Message**: `Client behaves wrong so the replication was canceled. Mostly happens if the client tries to write data that it is not allowed to`

**Cause**: The server rejected the replication request.

**Fix**: Check server permissions and logs.

**Docs**: https://rxdb.info/replication.html?console=errors&code=RC_FORBIDDEN

---

## undefined

**Message**: `fieldnames do not match the regex`

**Cause**: A field name in the schema contains invalid characters.

**Fix**: Use only allowed characters (a-z, A-Z, 0-9, _, -).

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC1

---

## undefined

**Message**: `SchemaCheck: name 'item' reserved for array-fields`

**Cause**: You used "item" as a field name, but it is reserved.

**Fix**: Rename the field.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC2

---

## undefined

**Message**: `SchemaCheck: fieldname has a ref-array but items-type is not string`

**Cause**: You defined a reference array but the items are not of type string.

**Fix**: Set the items type to string.

**Docs**: https://rxdb.info/population.html?console=errors&code=SC3

---

## undefined

**Message**: `SchemaCheck: fieldname has a ref but is not type string, [string,null] or array<string>`

**Cause**: You defined a reference field but the type is not string or array of strings.

**Fix**: Set the type to string or array of strings.

**Docs**: https://rxdb.info/population.html?console=errors&code=SC4

---

## undefined

**Message**: `SchemaCheck: primary can only be defined at top-level`

**Cause**: You defined the primary key in a nested object.

**Fix**: Move the primary key definition to the top level.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC6#primary-key

---

## undefined

**Message**: `SchemaCheck: default-values can only be defined at top-level`

**Cause**: You defined a default value in a nested object.

**Fix**: Move default values to the top level.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC7

---

## undefined

**Message**: `SchemaCheck: first level-fields cannot start with underscore _`

**Cause**: A top-level field name starts with an underscore.

**Fix**: Rename the field.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC8

---

## undefined

**Message**: `SchemaCheck: schema defines ._rev, this will be done automatically`

**Cause**: You defined _rev in your schema.

**Fix**: Remove _rev from the schema.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC10

---

## undefined

**Message**: `SchemaCheck: schema needs a number >=0 as version`

**Cause**: The version field is missing or invalid.

**Fix**: Set a valid version number (>=0).

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC11#version

---

## undefined

**Message**: `SchemaCheck: primary is always index, do not declare it as index`

**Cause**: You declared the primary key as an index, which is redundant.

**Fix**: Remove index: true from the primary key field.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC13

---

## undefined

**Message**: `SchemaCheck: primary is always unique, do not declare it as index`

**Cause**: You declared the primary key as unique, which is redundant.

**Fix**: Remove unique: true from the primary key field.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC14

---

## undefined

**Message**: `SchemaCheck: primary cannot be encrypted`

**Cause**: You tried to encrypt the primary key.

**Fix**: Primary keys cannot be encrypted.

**Docs**: https://rxdb.info/encryption.html?console=errors&code=SC15

---

## undefined

**Message**: `SchemaCheck: primary must have type: string`

**Cause**: The primary key field has a type other than string.

**Fix**: Set the primary key type to string.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC16#primary-key

---

## undefined

**Message**: `SchemaCheck: top-level fieldname is not allowed. See https://rxdb.info/rx-schema.html?console=toplevel#non-allowed-properties `

**Cause**: You used a reserved name for a top-level field.

**Fix**: Rename the field.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC17

---

## undefined

**Message**: `SchemaCheck: indexes must be an array`

**Cause**: The indexes property is not an array.

**Fix**: Set indexes to an array of strings or arrays.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC18#indexes

---

## undefined

**Message**: `SchemaCheck: indexes must contain strings or arrays of strings`

**Cause**: An index definition is invalid.

**Fix**: Ensure indexes are strings or arrays of strings.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC19#indexes

---

## undefined

**Message**: `SchemaCheck: indexes.array must contain strings`

**Cause**: A compound index contains non-string values.

**Fix**: Ensure compound indexes contain only strings.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC20#indexes

---

## undefined

**Message**: `SchemaCheck: given index is not defined in schema`

**Cause**: You defined an index for a field that does not exist.

**Fix**: Check the field name in the index.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC21#indexes

---

## undefined

**Message**: `SchemaCheck: given indexKey is not type:string`

**Cause**: You defined an index on a non-string field.

**Fix**: Indexes are only supported on string fields (mostly).

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC22#indexes

---

## undefined

**Message**: `SchemaCheck: fieldname is not allowed`

**Cause**: You used a field name that is not allowed (e.g. starts with $ or _).

**Fix**: Rename the field.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC23

---

## undefined

**Message**: `SchemaCheck: required fields must be set via array. See https://spacetelescope.github.io/understanding-json-schema/reference/object.html#required`

**Cause**: The required fields are not defined as an array of strings.

**Fix**: Set required to an array of strings.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC24

---

## undefined

**Message**: `SchemaCheck: compoundIndexes needs to be specified in the indexes field`

**Cause**: Compound indexes are not defined correctly.

**Fix**: Define compound indexes in the indexes array.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC25#indexes

---

## undefined

**Message**: `SchemaCheck: indexes needs to be specified at collection schema level`

**Cause**: Indexes are defined at the wrong level (e.g. inside properties).

**Fix**: Move indexes to the top level of the schema.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC26#indexes

---

## undefined

**Message**: `SchemaCheck: encrypted fields is not defined in the schema`

**Cause**: You tried to use encryption but encrypted fields are not defined.

**Fix**: Define encrypted fields in the schema.

**Docs**: https://rxdb.info/encryption.html?console=errors&code=SC28

---

## undefined

**Message**: `SchemaCheck: missing object key 'properties'`

**Cause**: The schema is missing the "properties" field.

**Fix**: Add the "properties" field to the schema.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC29

---

## undefined

**Message**: `SchemaCheck: primaryKey is required`

**Cause**: The schema is missing a primary key.

**Fix**: Define a primary key in the schema.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC30#primary-key

---

## undefined

**Message**: `SchemaCheck: primary field must have the type string/number/integer`

**Cause**: The primary key field has an invalid type.

**Fix**: Set the primary key type to string, number, or integer.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC32#primary-key

---

## undefined

**Message**: `SchemaCheck: used primary key is not a property in the schema`

**Cause**: The primary key field is not defined in the properties.

**Fix**: Add the primary key field to the properties.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC33#primary-key

---

## undefined

**Message**: `Fields of type string that are used in an index, must have set the maxLength attribute in the schema`

**Cause**: A string field used in an index is missing the maxLength attribute.

**Fix**: Set maxLength for the field.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC34#indexes

---

## undefined

**Message**: `Fields of type number/integer that are used in an index, must have set the multipleOf attribute in the schema`

**Cause**: A number field used in an index is missing the multipleOf attribute.

**Fix**: Set multipleOf for the field.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC35#indexes

---

## undefined

**Message**: `A field of this type cannot be used as index`

**Cause**: You tried to index a field type that cannot be indexed (e.g. object, array).

**Fix**: Remove the index or change the field type.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC36#indexes

---

## undefined

**Message**: `Fields of type number that are used in an index, must have set the minimum and maximum attribute in the schema`

**Cause**: A number field used in an index is missing minimum/maximum attributes.

**Fix**: Set minimum and maximum for the field.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC37#indexes

---

## undefined

**Message**: `Fields of type boolean that are used in an index, must be required in the schema`

**Cause**: A boolean field used in an index is not marked as required.

**Fix**: Mark the field as required.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC38#indexes

---

## undefined

**Message**: `The primary key must have the maxLength attribute set. Ensure you use the dev-mode plugin when developing with RxDB.`

**Cause**: The primary key field is missing the maxLength attribute.

**Fix**: Set maxLength for the primary key.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC39#primary-key

---

## undefined

**Message**: `$ref fields in the schema are not allowed. RxDB cannot resolve related schemas because it would have a negative performance impact.It would have to run http requests on runtime. $ref fields should be resolved during build time.`

**Cause**: You used $ref in the schema, which is not supported at runtime.

**Fix**: Resolve $ref fields during build time.

**Docs**: https://rxdb.info/rx-schema.html?console=errors&code=SC40

---

## undefin