When Firefox ver. 143.0.4 (64bit) is opened, I see many tiny groups of black dots withing the whole of the desktop display of this Firefox. From these black dots I see coloured lines traveling across the desktop within the Firefox desktop display. As I move the mouse these coloured lined move, disappear, and move around. Can you offer any suggestions. I am using Ubuntu UALinux Gamepack 22.04, The version of Firefox is an upgrade provided by Firefox updates. I have tried to uninstall this version of Firefox, same effect occuring. I have manually deleted every referance to Firefox, as this worked in UALinux Gamepack 20.04. I have used sudo apt update, sudo apt upgrade, sudo apt --fix-broken install, and sudo dpkg --configure -a. None of these can fix this problem. I restarted my Firefox today with the same problem, and found in the Help dropdown menu, and found troubleshoot mode. When I opened in troubleshoot mode, all these problems are not there any more. Can you offer any help ?????? P.S. I tryed to take a screenshot of this problem, but the screenshot doesn't show this problem ?