I upgraded from 10.10. Then everything worked well except very important one -- my terminal.

I try to open my terminal, but no any window popup. I press alt+tab and the windows switcher appears in which there is the terminal. I switch to it, however, nothing happens.

I can see the word terminal in my top bar. When I move cursor on it I see the file edit view and so on. But they are useless unless I can find my terminal window.

I have no problem with chrome, firefox, eclipse, ubuntu software center, pidgin and many more applications. But without terminal, I'm using a disabled linux.