>>My files in my library are AIFF Files which work without any issues on XDJ or CDJs.
Does it mean the music files work when loading from a USB drive, or XDJ or CDJs can load properly in Link Export?
If you export the tracks that give the error to a USB drive and load the tracks on the XDJ-XZ, do they load?
If the tracks are loadable on the XDJ or CDJ in Link Export, it seems effective to inspect the XDJ-XZ at an authorized service center.
If you want us to check the music files, please send the tracks that have the error. We will see if we can replicate the issue.
In that case please file an inquiry ticket here and our support team will gather some additional information to assist you in resolving this issue.
You might also want to try to convert tracks to AIFF again or another format and see if that helps the issue.