My iTunes XML export has not been working for months but I need it for DJ software like Traktor Pro. I would like to find and fix the problem and can't reset the database.

When trying to export the whole library as XML manually (File -> Library -> Export Library) I can see Assertion failure: success == noErr (-8753) in the system log but that is ALL I know right now.

What can I do find the root cause of this problem?

macOS version: 10.12.5
iTunes version: 12.6.1.25

These are my relevant settings: