# AppKit Errors These constants represent errors generated by AppKit. ## Discussion The returned constants from an `NSError` object. ## Topics ### Error Codes [`NSFontAssetDownloadError`](/documentation/AppKit/NSFontAssetDownloadError) [`NSFontErrorMaximum`](/documentation/AppKit/NSFontErrorMaximum) [`NSFontErrorMinimum`](/documentation/AppKit/NSFontErrorMinimum) [`NSTextReadInapplicableDocumentTypeError`](/documentation/AppKit/NSTextReadInapplicableDocumentTypeError) Indicates a problem reading data with the specified format. [`NSTextWriteInapplicableDocumentTypeError`](/documentation/AppKit/NSTextWriteInapplicableDocumentTypeError) Indicates a problem writing data of the specified format. [`NSTextReadWriteErrorMinimum`](/documentation/AppKit/NSTextReadWriteErrorMinimum) The beginning of a range of error codes reserved for future use. [`NSTextReadWriteErrorMaximum`](/documentation/AppKit/NSTextReadWriteErrorMaximum) The end of a range of error codes reserved for future use. [`NSServiceApplicationLaunchFailedError`](/documentation/AppKit/NSServiceApplicationLaunchFailedError) The service providing application could not be launched. This will typically contain an underlying error with an Launch Services error code. [`NSServiceApplicationNotFoundError`](/documentation/AppKit/NSServiceApplicationNotFoundError) The service provider could not be found. [`NSServiceErrorMaximum`](/documentation/AppKit/NSServiceErrorMaximum) Inclusive service error range, for checking future error codes. [`NSServiceErrorMinimum`](/documentation/AppKit/NSServiceErrorMinimum) Inclusive service error range, for checking future error codes. [`NSServiceInvalidPasteboardDataError`](/documentation/AppKit/NSServiceInvalidPasteboardDataError) The service providing app did not return a pasteboard with any of the promised types, or we couldn’t write the data from the pasteboard to the object receiving the returned data. [`NSServiceMalformedServiceDictionaryError`](/documentation/AppKit/NSServiceMalformedServiceDictionaryError) The service dictionary did not contain the necessary keys. Messages will typically be logged to the console giving more details. [`NSServiceMiscellaneousError`](/documentation/AppKit/NSServiceMiscellaneousError) Other errors, representing programmatic mistakes in the service consuming application. These show a generic error message to the user. [`NSServiceRequestTimedOutError`](/documentation/AppKit/NSServiceRequestTimedOutError) The service providing application did not open its service listening port in time, or the app didn’t respond to the request in time; see the Console log to figure out which (the errors are typically reported the same way to the user). [`NSSharingServiceErrorMaximum`](/documentation/AppKit/NSSharingServiceErrorMaximum) [`NSSharingServiceErrorMinimum`](/documentation/AppKit/NSSharingServiceErrorMinimum) [`NSSharingServiceNotConfiguredError`](/documentation/AppKit/NSSharingServiceNotConfiguredError) [`var NSWorkspaceAuthorizationInvalidError: Int`](/documentation/AppKit/NSWorkspaceAuthorizationInvalidError) The provided workspace authorization credentials expired or are invalid. [`var NSWorkspaceErrorMaximum: Int`](/documentation/AppKit/NSWorkspaceErrorMaximum) [`var NSWorkspaceErrorMinimum: Int`](/documentation/AppKit/NSWorkspaceErrorMinimum) [`var NSWindowSharingErrorMaximum: Int`](/documentation/AppKit/NSWindowSharingErrorMaximum) [`var NSWindowSharingErrorMinimum: Int`](/documentation/AppKit/NSWindowSharingErrorMinimum) [`var NSWindowSharingRequestAlreadyRequested: Int`](/documentation/AppKit/NSWindowSharingRequestAlreadyRequested) [`var NSWindowSharingRequestNoEligibleSession: Int`](/documentation/AppKit/NSWindowSharingRequestNoEligibleSession) [`var NSWindowSharingRequestUnspecifiedError: Int`](/documentation/AppKit/NSWindowSharingRequestUnspecifiedError) [`var NSPasteboardMiscellaneousError: Int`](/documentation/AppKit/NSPasteboardMiscellaneousError) [`var NSPasteboardCommunicationError: Int`](/documentation/AppKit/NSPasteboardCommunicationError) [`var NSPasteboardInvalidArgumentError: Int`](/documentation/AppKit/NSPasteboardInvalidArgumentError) [`var NSPasteboardContentsNotAvailableError: Int`](/documentation/AppKit/NSPasteboardContentsNotAvailableError) [`var NSPasteboardErrorMinimum: Int`](/documentation/AppKit/NSPasteboardErrorMinimum) [`var NSPasteboardErrorMaximum: Int`](/documentation/AppKit/NSPasteboardErrorMaximum) --- 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)