Settings are suddenly not visible - where did they go?

Yesterday I installed fresh Ubuntu 20.04.2.0 LTS and everything looked fine. But today the settings are not visible. It shows that settings are opened with a red dot, but there's nothing to see.

My configuration is not available to see also.

What is the problem and how can I fix it?

Solution 1:

Thanks for your efforts to help me but I already found the solution.

Well, it was a silly mistake that I did it. I wanted to watch a movie and I plugged an HDMI cable into the laptop just to see how it works with the fresh installed Ubuntu.

So, after I unplugged the cable everything was fine... but when I plugged the cable in again the same thing happened.

Then I opened the settings in Display and changed the option from Join Displays to Mirror.

That was the key, the Mirror option.

Thanks :)