Recurring Error Message

The message indicates that the mp4 file (975_0891 MP4) can't be found where the FCP XML indicates that it should be, if you have deleted it from your library that is to be expected. It appears that you have not removed all references to this file in your project and it is still needed to be able to create the AAF. If you can post the FCP XML I can confirm this and tell you where on your timeline it still exists.

I am using fcp 10.1.3
OS X El Capitain 10.11.4
X2Pro LE (pro upgrade)

I keep getting this error message:

An error occurred converting Final Cut XML to AAF

Writing AAF file
Adding assets to AAF file
Adding essence for asset [975_0891 MP4] to AAF file
Opening audio extractor for portion 0 of asset [975_0891 MP4]
Failed to initialise audio extractor with default bit depth of 16
Error Setting up for audio extraction (The requested URL was not found on this server.)

Suggestion: Does this movie contain an unsupported audio format ?

No AAF file has been generated.
X2Pro Audio Convert LE 3.0.13[/

The first time I got this error I went back into my fcp project and removed the 975_0891 mp4 file that seemed to be causing the problem. But I'm still getting this same error message after removing the 975_0891 mp4 file from the project as well as completely deleting it from my fcp library. Please help me narrow down the issue