I have been unable to overcome this error in Application Loader. I\'ve quit, restarted, tried different computers - it\'s like the server is hung up on an op that I never i
It might be because Xcode crashed as you were uploading your app. Either, all you need to do is delete the token files:
Open Terminal on your Mac, and paste:
rm ~/.itmstransporter/UploadTokens/*.token
That should clear it. If it still doesn't work (at this point you should try re-uploading your app), run that command on Terminal again, or manually go to...
/Users//.itmstransporter/UploadTokens/
...and delete all the .token files.
Hope that helps!