I still can't reproduce this but I think I found the problem `/usr/share/applications/audacious.desktop` has MIME-type 'inode/directory'. Someone in #ubuntu-mate IRC channel had the same issue and purging Audacious restored the correct behaviour.
I still can't reproduce this but I think I found the problem `/usr/share/ applications/ audacious. desktop` has MIME-type 'inode/directory'. Someone in #ubuntu-mate IRC channel had the same issue and purging Audacious restored the correct behaviour.