# File System Error Codes Recognize common error codes generated by file system operations. ## Topics ### Error Codes [`NSFileNoSuchFileError`](/documentation/Foundation/NSFileNoSuchFileError-swift.var) A filesystem operation was attempted on a non-existent file. [`NSFileLockingError`](/documentation/Foundation/NSFileLockingError-swift.var) The file could not be locked. [`NSFileReadUnknownError`](/documentation/Foundation/NSFileReadUnknownError-swift.var) Could not read, for unknown reasons. [`NSFileReadNoPermissionError`](/documentation/Foundation/NSFileReadNoPermissionError-swift.var) Could not read because of a permission problem. [`NSFileReadInvalidFileNameError`](/documentation/Foundation/NSFileReadInvalidFileNameError-swift.var) Could not read because of an invalid file name. [`NSFileReadCorruptFileError`](/documentation/Foundation/NSFileReadCorruptFileError-swift.var) Could not read because of a corrupted file, bad format, or similar reason. [`NSFileReadNoSuchFileError`](/documentation/Foundation/NSFileReadNoSuchFileError-swift.var) Could not read because no such file was found. [`NSFileReadInapplicableStringEncodingError`](/documentation/Foundation/NSFileReadInapplicableStringEncodingError-swift.var) Could not read because the string encoding wasn’t applicable. [`NSFileReadUnsupportedSchemeError`](/documentation/Foundation/NSFileReadUnsupportedSchemeError-swift.var) Could not read because the specified URL scheme is unsupported. [`NSFileReadTooLargeError`](/documentation/Foundation/NSFileReadTooLargeError-swift.var) Could not read because the specified file was too large. [`NSFileReadUnknownStringEncodingError`](/documentation/Foundation/NSFileReadUnknownStringEncodingError-swift.var) Could not read because the string coding of the file couldn’t be determined. [`NSFileWriteUnknownError`](/documentation/Foundation/NSFileWriteUnknownError-swift.var) Could not write, for unknown reasons. [`NSFileWriteNoPermissionError`](/documentation/Foundation/NSFileWriteNoPermissionError-swift.var) Could not write because of a permission problem. [`NSFileWriteInvalidFileNameError`](/documentation/Foundation/NSFileWriteInvalidFileNameError-swift.var) Could not write because of an invalid file name. [`NSFileWriteFileExistsError`](/documentation/Foundation/NSFileWriteFileExistsError-swift.var) Could not perform an operation because the destination file already exists. [`NSFileWriteInapplicableStringEncodingError`](/documentation/Foundation/NSFileWriteInapplicableStringEncodingError-swift.var) Could not write because the string encoding was not applicable. [`NSFileWriteUnsupportedSchemeError`](/documentation/Foundation/NSFileWriteUnsupportedSchemeError-swift.var) Could not write because the specified URL scheme is unsupported. [`NSFileWriteOutOfSpaceError`](/documentation/Foundation/NSFileWriteOutOfSpaceError-swift.var) Could not write because of a lack of disk space. [`NSFileWriteVolumeReadOnlyError`](/documentation/Foundation/NSFileWriteVolumeReadOnlyError-swift.var) Could not write because the volume is read-only. [`NSFileManagerUnmountBusyError`](/documentation/Foundation/NSFileManagerUnmountBusyError-swift.var) The volume couldn’t be unmounted because it’s in use. [`NSFileManagerUnmountUnknownError`](/documentation/Foundation/NSFileManagerUnmountUnknownError-swift.var) The volume couldn’t be unmounted, for unknown reasons. [`NSFileErrorMinimum`](/documentation/Foundation/NSFileErrorMinimum-swift.var) The start of the range of error codes reserved for file errors. [`NSFileErrorMaximum`](/documentation/Foundation/NSFileErrorMaximum-swift.var) The end of the range of error codes reserved for file errors. [`NSFileNoSuchFileError`](/documentation/Foundation/NSFileNoSuchFileError-c.enum.case) A filesystem operation was attempted on a non-existent file. [`NSFileLockingError`](/documentation/Foundation/NSFileLockingError-c.enum.case) The file could not be locked. [`NSFileReadUnknownError`](/documentation/Foundation/NSFileReadUnknownError-c.enum.case) Could not read, for unknown reasons. [`NSFileReadNoPermissionError`](/documentation/Foundation/NSFileReadNoPermissionError-c.enum.case) Could not read because of a permission problem. [`NSFileReadInvalidFileNameError`](/documentation/Foundation/NSFileReadInvalidFileNameError-c.enum.case) Could not read because of an invalid file name. [`NSFileReadCorruptFileError`](/documentation/Foundation/NSFileReadCorruptFileError-c.enum.case) Could not read because of a corrupted file, bad format, or similar reason. [`NSFileReadNoSuchFileError`](/documentation/Foundation/NSFileReadNoSuchFileError-c.enum.case) Could not read because no such file was found. [`NSFileReadInapplicableStringEncodingError`](/documentation/Foundation/NSFileReadInapplicableStringEncodingError-c.enum.case) Could not read because the string encoding wasn’t applicable. [`NSFileReadUnsupportedSchemeError`](/documentation/Foundation/NSFileReadUnsupportedSchemeError-c.enum.case) Could not read because the specified URL scheme is unsupported. [`NSFileReadTooLargeError`](/documentation/Foundation/NSFileReadTooLargeError-c.enum.case) Could not read because the specified file was too large. [`NSFileReadUnknownStringEncodingError`](/documentation/Foundation/NSFileReadUnknownStringEncodingError-c.enum.case) Could not read because the string coding of the file couldn’t be determined. [`NSFileWriteUnknownError`](/documentation/Foundation/NSFileWriteUnknownError-c.enum.case) Could not write, for unknown reasons. [`NSFileWriteNoPermissionError`](/documentation/Foundation/NSFileWriteNoPermissionError-c.enum.case) Could not write because of a permission problem. [`NSFileWriteInvalidFileNameError`](/documentation/Foundation/NSFileWriteInvalidFileNameError-c.enum.case) Could not write because of an invalid file name. [`NSFileWriteFileExistsError`](/documentation/Foundation/NSFileWriteFileExistsError-c.enum.case) Could not perform an operation because the destination file already exists. [`NSFileWriteInapplicableStringEncodingError`](/documentation/Foundation/NSFileWriteInapplicableStringEncodingError-c.enum.case) Could not write because the string encoding was not applicable. [`NSFileWriteUnsupportedSchemeError`](/documentation/Foundation/NSFileWriteUnsupportedSchemeError-c.enum.case) Could not write because the specified URL scheme is unsupported. [`NSFileWriteOutOfSpaceError`](/documentation/Foundation/NSFileWriteOutOfSpaceError-c.enum.case) Could not write because of a lack of disk space. [`NSFileWriteVolumeReadOnlyError`](/documentation/Foundation/NSFileWriteVolumeReadOnlyError-c.enum.case) Could not write because the volume is read-only. [`NSFileManagerUnmountBusyError`](/documentation/Foundation/NSFileManagerUnmountBusyError-c.enum.case) The volume couldn’t be unmounted because it’s in use. [`NSFileManagerUnmountUnknownError`](/documentation/Foundation/NSFileManagerUnmountUnknownError-c.enum.case) The volume couldn’t be unmounted, for unknown reasons. [`NSFileErrorMinimum`](/documentation/Foundation/NSFileErrorMinimum-c.enum.case) The start of the range of error codes reserved for file errors. [`NSFileErrorMaximum`](/documentation/Foundation/NSFileErrorMaximum-c.enum.case) The end of the range of error codes reserved for file errors. --- 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)