[Risgah]

Not one command I ever tried wrote anything into the changes.dat file.

Try using "--local Nas/ --prefix smb://192.168.1.10:/" instead of "--local Nas/Disk1/Movies --prefix smb://192.168.1.10:/Disk1/Movies".

If you want to see what the script is doing, enable the debug option "--verbose".

Once the script has finished running, check what is in the changes.dat file - it should be a list of changes that will set artwork for various movies to a blank value, ie. nothing, which will remove the artwork from the media library. If you're happy with the changes, apply it to your media library with "type changes.dat | python texturecache.py set"

The only output in the cmd window after your command is:
Progress: 'number of movies' of 'number of movies'

With --verbose there are these lines for every movie
##DEBUG## mediatype [movie]; mediatitle [movie name]
##DEBUG## mediafile is [smb://192.168.1.10/Disk1/Movies/filename.avi]
##DEBUG## local root name would be [Nas\Disk1\Movies\filename.avi]

Edit:

Ah, I did not add or specify any --artwork. Now it did populate the dat.file. I always thought without --artwork mklocal.py would do it all.