# Validation error codes Error codes relating to the validation of managed objects. ## Discussion For additional error codes, including `NSValidationErrorMinimum` and `NSValidationErrorMaximum`, see . ## Topics ### Error codes [`var NSCoreDataError: Int`](/documentation/CoreData/NSCoreDataError) An error code that indicates a nonspecific Core Data error. [`var NSEntityMigrationPolicyError: Int`](/documentation/CoreData/NSEntityMigrationPolicyError) An error code that indicates a migration failure during processing of an entity migration policy. [`var NSExternalRecordImportError: Int`](/documentation/CoreData/NSExternalRecordImportError) Error code to denote a general error encountered while importing external records. [`var NSInferredMappingModelError: Int`](/documentation/CoreData/NSInferredMappingModelError) Error code to denote a problem with the creation of an inferred mapping model. [`var NSManagedObjectConstraintMergeError: Int`](/documentation/CoreData/NSManagedObjectConstraintMergeError) Error code to denote a problem with the merging of instances of a managed object. [`var NSManagedObjectConstraintValidationError: Int`](/documentation/CoreData/NSManagedObjectConstraintValidationError) Error code to denote a problem with the validation of a managed object. [`var NSManagedObjectContextLockingError: Int`](/documentation/CoreData/NSManagedObjectContextLockingError) Error code to denote an inability to acquire a lock in a managed object context. [`var NSManagedObjectExternalRelationshipError: Int`](/documentation/CoreData/NSManagedObjectExternalRelationshipError) Error code to denote that an object being saved has a relationship containing an object from another store. [`var NSManagedObjectMergeError: Int`](/documentation/CoreData/NSManagedObjectMergeError) Error code to denote that a merge policy failed—Core Data is unable to complete merging. [`var NSManagedObjectModelReferenceNotFoundError: Int`](/documentation/CoreData/NSManagedObjectModelReferenceNotFoundError) An error code that indicates Core Data isn’t able to find or instantiate the referenced object model. [`var NSManagedObjectReferentialIntegrityError: Int`](/documentation/CoreData/NSManagedObjectReferentialIntegrityError) Error code to denote an attempt to fire a fault pointing to an object that does not exist. [`var NSManagedObjectValidationError: Int`](/documentation/CoreData/NSManagedObjectValidationError) Error code to denote a generic validation error. [`var NSMigrationCancelledError: Int`](/documentation/CoreData/NSMigrationCancelledError) Error code to denote that migration failed due to manual cancellation. [`var NSMigrationConstraintViolationError: Int`](/documentation/CoreData/NSMigrationConstraintViolationError) Error code to denote a problem with the validation of a managed object during a migration. [`var NSMigrationError: Int`](/documentation/CoreData/NSMigrationError) Error code to denote a general migration error. [`var NSMigrationManagerDestinationStoreError: Int`](/documentation/CoreData/NSMigrationManagerDestinationStoreError) Error code to denote that migration failed due to a problem with the destination data store. [`var NSMigrationManagerSourceStoreError: Int`](/documentation/CoreData/NSMigrationManagerSourceStoreError) Error code to denote that migration failed due to a problem with the source data store. [`var NSMigrationMissingMappingModelError: Int`](/documentation/CoreData/NSMigrationMissingMappingModelError) Error code to denote that migration failed due to a missing mapping model. [`var NSMigrationMissingSourceModelError: Int`](/documentation/CoreData/NSMigrationMissingSourceModelError) Error code to denote that migration failed due to a missing source data model. [`var NSPersistentHistoryTokenExpiredError: Int`](/documentation/CoreData/NSPersistentHistoryTokenExpiredError) Error code to denote that the persistent history token has expired. [`var NSPersistentStoreCoordinatorLockingError: Int`](/documentation/CoreData/NSPersistentStoreCoordinatorLockingError) Error code to denote an inability to acquire a lock in a persistent store. [`var NSPersistentStoreIncompatibleSchemaError: Int`](/documentation/CoreData/NSPersistentStoreIncompatibleSchemaError) Error code to denote that a persistent store returned an error for a save operation. [`var NSPersistentStoreIncompatibleVersionHashError: Int`](/documentation/CoreData/NSPersistentStoreIncompatibleVersionHashError) Error code to denote that entity version hashes in the store are incompatible with the current managed object model. [`var NSPersistentStoreIncompleteSaveError: Int`](/documentation/CoreData/NSPersistentStoreIncompleteSaveError) Error code to denote that one or more of the stores returned an error during a save operations. [`var NSPersistentStoreInvalidTypeError: Int`](/documentation/CoreData/NSPersistentStoreInvalidTypeError) Error code to denote an unknown persistent store type/format/version. [`var NSPersistentStoreOpenError: Int`](/documentation/CoreData/NSPersistentStoreOpenError) Error code to denote an error occurred while attempting to open a persistent store. [`var NSPersistentStoreOperationError: Int`](/documentation/CoreData/NSPersistentStoreOperationError) Error code to denote that a persistent store operation failed. [`var NSPersistentStoreSaveConflictsError: Int`](/documentation/CoreData/NSPersistentStoreSaveConflictsError) Error code to denote that an unresolved merge conflict was encountered during a save. . [`var NSPersistentStoreSaveError: Int`](/documentation/CoreData/NSPersistentStoreSaveError) Error code to denote that a persistent store returned an error for a save operation. [`var NSPersistentStoreTimeoutError: Int`](/documentation/CoreData/NSPersistentStoreTimeoutError) Error code to denote that Core Data failed to connect to a persistent store within the time specified by `NSPersistentStoreTimeoutOption`. [`var NSPersistentStoreTypeMismatchError: Int`](/documentation/CoreData/NSPersistentStoreTypeMismatchError) Error code returned by a persistent store coordinator if a store is accessed that does not match the specified type. [`var NSPersistentStoreUnsupportedRequestTypeError: Int`](/documentation/CoreData/NSPersistentStoreUnsupportedRequestTypeError) Error code to denote that an `NSPersistentStore` subclass was passed a request (an instance of [`NSPersistentStoreRequest`](/documentation/CoreData/NSPersistentStoreRequest)) that it did not understand. [`var NSSQLiteError: Int`](/documentation/CoreData/NSSQLiteError) Error code to denote a general SQLite error. [`var NSStagedMigrationBackwardMigrationError: Int`](/documentation/CoreData/NSStagedMigrationBackwardMigrationError) An error code that indicates a failed migration because of an attempt to migrate backward. [`var NSStagedMigrationFrameworkVersionMismatchError: Int`](/documentation/CoreData/NSStagedMigrationFrameworkVersionMismatchError) An error code that indicates a failed migration because the persistent store’s metadata doesn’t support staged lightweight migrations. [`var NSValidationInvalidURIError: Int`](/documentation/CoreData/NSValidationInvalidURIError) Error code to denote a problem with the validation of a URI property. [`var NSValidationMultipleErrorsError: Int`](/documentation/CoreData/NSValidationMultipleErrorsError) Error code to denote an error containing multiple validation errors. [`var NSValidationMissingMandatoryPropertyError: Int`](/documentation/CoreData/NSValidationMissingMandatoryPropertyError) Error code for a non-optional property with a nil value. [`var NSValidationRelationshipLacksMinimumCountError: Int`](/documentation/CoreData/NSValidationRelationshipLacksMinimumCountError) Error code to denote a to-many relationship with too few destination objects. [`var NSValidationRelationshipExceedsMaximumCountError: Int`](/documentation/CoreData/NSValidationRelationshipExceedsMaximumCountError) Error code to denote a bounded to-many relationship with too many destination objects. [`var NSValidationRelationshipDeniedDeleteError: Int`](/documentation/CoreData/NSValidationRelationshipDeniedDeleteError) Error code to denote some relationship with delete rule `NSDeleteRuleDeny` is non-empty. [`var NSValidationNumberTooLargeError: Int`](/documentation/CoreData/NSValidationNumberTooLargeError) Error code to denote some numerical value is too large. [`var NSValidationNumberTooSmallError: Int`](/documentation/CoreData/NSValidationNumberTooSmallError) Error code to denote some numerical value is too small. [`var NSValidationDateTooLateError: Int`](/documentation/CoreData/NSValidationDateTooLateError) Error code to denote some date value is too late. [`var NSValidationDateTooSoonError: Int`](/documentation/CoreData/NSValidationDateTooSoonError) Error code to denote some date value is too soon. [`var NSValidationInvalidDateError: Int`](/documentation/CoreData/NSValidationInvalidDateError) Error code to denote some date value fails to match date pattern. [`var NSValidationStringTooLongError: Int`](/documentation/CoreData/NSValidationStringTooLongError) Error code to denote some string value is too long. [`var NSValidationStringTooShortError: Int`](/documentation/CoreData/NSValidationStringTooShortError) Error code to denote some string value is too short. [`var NSValidationStringPatternMatchingError: Int`](/documentation/CoreData/NSValidationStringPatternMatchingError) Error code to denote some string value fails to match some pattern. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)