The /CNext01.roll/DOC4.CATPart bit comes from an incremental or auto backup. The directory you listed is where Catia stores in-process backup files. You can see those files in the directory while your session is active. When you exit Catia correctly, those files are all deleted. If you exit Catia incorrectly, i.e. it crashes, those files will be left there to potentially create a warm start. The files are named DOC1.CATPart, DOC2.CATProduct, etc.
In your case, it appears that a file ended up with a link (incorrectly I imagine) to a temporary backup file, that then clearly got deleted.
I don't know how then to solve your problem, but perhaps this information will point you in the right direction. More work with CATDUA is my best guess. I'm not quite an expert, but this is what I have seen in my experience.
Cheers,
Mark