Can't kill Preview app I have strange problem, my Preview app is not responding and can't kill it.

leo-mac:~ leo$ sudo killall Preview
No matching processes were found

Force Quit button also doesn't give any result.
ps (and Activity Monitor) is empty:
leo-mac:~ leo$ ps -ax | grep -i preview
24793 ttys000    0:00.00 grep -i preview

It's not a zombie because next command is also empty:
ps aux | awk '&quot;[Zz]&quot; ~ $8 { printf(&quot;%s, PID = %d\n&quot;, $8, $2); }'
I really can't understand what happened. Any ideas?
I had the same problem. Workaround:

sudo killall launchservicesd
sudo killall Dock