It started after I updated my BIOS settings (virtualization and fast boot). I think I returned them back in place, although I might have changed something and forgot. But my system can't boot normally now for some reason and I don't know what's wrong and what should I check to fix it.
I only see GDM loading bar and then blinking of blank screen with occasional terminal on the startup. I managed to switch to another terminal before but it seems that now I can't even do that -- the login prompt is replaced with black screen again after 2 seconds.
I had a lot of pain setting up the system already, mainly because of the new nvidia card. But now I'm not sure what to check for.
The Secure Boot option is disabled, so that is not the problem.