[DaveBlake]

So I tested my problematic files with the build from Github and it worked using the separator with blanks.
The genre browsing is working again aswell.
Thank you very much!

Thanks for testing it. Testing my own work is never the best thing, users sometimes come up with things I would never have thought of, so always good to have user testing.

Maybe I will retag everything again then

Enjoy
There is satisfaction in a well tagged library.

Is this fix going to be implemented in the final Jarvis release?

Yes, especially now it has been tested

One more question regarding the AC/DC issue.
I always used to tag AC/DC as AC DC and never had problems with it this way.
Now, with the new fix, I should be able to leave AC/DC as it is right?

Yes, as long as slash (no spaces) is not the separator then "AC/DC" will be treated as a single artist name.

I always thought Kodi would have a problem with the location of the songs as the folder would be named "ACDC" (without the slash) in Windows.
How is Kodi handling this?

Kodi does not use the folder hierarchy to construct the library just the tags inside the music files, so the folders can be named how you like. You could even put all the tracks for many albums in one folder although I don't suggest you do that! It is more limited if you want to use NFO files to add extra album or artist info, or non embedded art work etc., so there are reasons for a logical folder layout rather than a big heap of files, but Kodi takes album title and artist name from tags not folders.