Today my laptop suddenly crashed, and after restart, the log-in screen changed (it looked like unity), and when I tried to log-in, I received the following error: " failed to load session "gnome" ". I went to recovery menu, tried to repair broken packages and update grub bootloader. It did not help. Now I have the same screen, but when I try to login, it says that I successfully logged in, but the log-in screen does not disappear and I can't do anything further.
Does anyone have any ideea what's wrong?