Hi, this is going to be a long one, so many things... Using Firefox the latest Ubuntu LTS, with the latest Firefox from Snap. I'm a very long term Firefox user, never had any real troubles unit recently. I have a vast number of cookies, saved passwords and so on. Reinstalling or deleting cookies or such isn't an option unless fixes are guaranteed to work - if I have to start over then I'll do it with Opera, that is where my grumpiness indicator is at. The set up is two monitors (working as a single 'screen') attached to an Aspire PC (Aspire X seems to be the model?). I tend to have 'stuff' going on in the left hand monitor, YouTube on the right. The PC is on all day. I know there are log files, but I don't know which is for what or where they are. I use AdBlocker Ultimate. So what's happening is: Firefox crashes quite often at any time - 'Firefox is not responding - force quit or wait' - always have to quit. There doesn't seem to be any repeatable way to cause this, it seems random. When the mouse enters the YouTube window (the drawing area, not the actual window) it disappears until the pointer moves out of the window. Jiggling the window size sometimes brings it back, but... When the mouse pointer actually appears the window is completely unresponsive - clicks don't work, nothing highlights and so on. After somewhere between 10 and 30 seconds things will work for 2 or 3 mouse actions (clicks, drags etc) then do it again. Unless I give it plenty of time, clicking on a video will play a pretty random one - Firefox seems to lose track of where the pointer is. If I comment on a video the I get about 5 to 10 characters in then nothing happens for 10 to 20 seconds, then any queued characters are shown. Rinse and repeat until the comment is complete - it takes ages. YouTube is the biggest problem, but there are some glitches in other Firefox windows, I'm supposing that the problems are audio/video related. None of the above happens with Opera. It's getting to the stage where Firefox is unusable. I've googled and searched this site but the there seems no solution. Any help appreciated.