Getting error while exporting a song from iPod

I have written the code to export a song from iPod to my app. When I try to export a song from iPod, I am getting following error message.

AVAssetExportSessionStatusFailed: Error Domain=AVFoundationErrorDomain Code=-11820 "Cannot Comp开发者_运维技巧lete Export" UserInfo=0x13b690 {NSLocalizedRecoverySuggestion=Try exporting again., NSLocalizedDescription=Cannot Complete Export}

Error Domain=AVFoundationErrorDomain Code=-11820 "Cannot Complete Export" UserInfo=0x13b690 {NSLocalizedRecoverySuggestion=Try exporting again., NSLocalizedDescription=Cannot Complete Export}

Please help me to resolve it.

Exporting to mp3 requires two steps: exporting to mov and extracting audio data from mov file to mp3. This library does the export: https://github.com/tapsquare/TSLibraryImport (I'm not an author, we are using it in our project).

There might be already another file present at that location with the same name. Delete the old file and this will work.