Can't Add or Edit Columns in Media Libary

[crumblydonut]

I used to be able to add and move columns in library, but now I can't.
I can only see the title and the time.
I can't rate tracks like I used to, since I can't add the rating column.

Right clicking along the top of media library doesn't work any more.

Any help would be much appreciated.

If I need to uninstall and reinstall, how do I preserve my playlists?