I can't shutdown my Late 2012 Mac mini, running El Capitan, in the normal way, by selecting the Shut Down... on the Apple menu. Every time I try, Finder vanishes and the shutdown progress freezes. I'm still able to work with the Dock, so I can shutdown using Terminal. In long term it's really annoying.
Hopefully someone has an idea whats wrong.
[EDIT] I just found out that im able to shut the system down by sign out and them use the displayed shutdown on the bottom.