In the firefox when I watch movie on Youtube in full screen the video don`t go to normal screen again. I click on minimine and nothing happens. Ctrl ALt del don't work in full screen and alt print and k. Only Alt print B works
You must watch a movie 2 hours to this bug work
how to add show desktop button
?
i can't save my keyboard layout here.

https://pastebin.com/YnbJZGzU

So, when you begin to watch a video in YouTube you can enter and exit from full-screen mode, as normal, but after about two hours, you can no longer do this?

What could be happening after two hours of CPU and graphics-intensive operation, that could lead to abnormal operation of your system? Are you running out of resources, or is there a thermal problem?

Is there any indication your computer is over-heating? Is the fan working or is there some blockage of air circulation? If you turn it off, wait a bit to let it cool down, and turn it on again, do you get normal operation again?

You can also install temperature-monitoring utilities to see if the abnormal behavior is associated with a temperature rise.

Do full screen videos exit properly for you in other browsers like Chrome or Chromium?

In chrome works well!

I use chromium exclusively and it works great. Never liked firefox.

I am very curious about this keyboard shortcut:

<Alt><Print Screen><B>

What is it supposed to do? My reference is Wikipedia's table of keyboard shortcuts, and I can't find it there.
Am I missing something??

escape key or double click on the (movie) screen for youtube.

Alt+printscreen+b restarts the system

^ i have to try that sometime.

all (!) the hardware is AMD; the GPU says "Trinity".
might be relevant.

OK, that's helpful. Firefox has crashed, but the 'system' is alive--because your keyboard is still responsive.

To diagnose what's happening, you have to duplicate the problem. Again, run YouTube full-screen (same video, if possible) for two hours, or however long it takes for Firefox to crash. But then, don't do a system reboot, but instead:
You should now be in terminal (TTY1). If there's anything at the prompt, clear it, with Then, do this:
Look at KiB Mem: and KiB Swap: and report how much was available, and most important, how much is free, at the time of the Firefox crash.
Then, see if this gets you back to your file manager desktop (I assume it's Moksha or Enlightenment?).
Terminate 'top':
Terminate the 'crashed' firefox:
Get back to the desktop:

If ctrl-alt-f1 doesn't work, try ctrl-alt-f2 then login., then you can run top and killall etc.

Also instead of that, you can always just try another desktop (alt-f2) to see if it's responding (and then open terminal from there), but that's less likely to work than ctrl-alt-f2.

At least for me, control-alt-f1 brings up some console terminal displaying all the startup messages but no way to get out of it...

Thanks for help! I am on Chrome in Moksha desktop!
If the problem comes back I will try the tips presented.