I recently upgraded my Kubuntu system from 18.04 to 18.10. An issue that I've been experiencing since the upgrade has been that Firefox 63.0 has started becoming unresponsive after resuming the system from a suspend. Once the system resume, the area of the screen that was taken up by Firefox becomes completely black and moving it around does not change anything. I've had to force quit the application ever single time I've resumed the system.
I've attempted running Firefox in safe mode before suspending, reinstalling Firefox both with apt remove and apt remove --purge. None of those have fixed it.
I am on kernel 4.18, using nVidia 396.54.09 and Firefox 63.0.
Any help would be appreciated. Thanks.
Unfortunately, its bug in Firefox - Bug #1492580 "Infinite loop in GLContext::RawGetErrorAndClear from endless GL_CONTEXT_LOST with Nvidia Linux drivers and suspend/resume"
There is no solution so far unless Mozilla undo change which caused it - Bug 1484782, which is part of preparation to enable WebRender on Linux
Bug was not present in Firefox 62 and was not fixed in time to "ride trains" of Firefox 63, so you may want either downgrade to Firefox 62 or to shutdown Firefox each time your going to suspend your system.
As noted in comments staying on Firefox 62 in long run may be not best idea, especially if Mozilla will drag on resolving this bug. In this case switching to Firefox ESR (based on Firefox 60) maybe better solution - https://www.mozilla.org/en-US/firefox/organizations/
It would not hurt also to get Mozilla informed that you DO suffer from this bug by posting in comment in Bugzilla' bug mentioned earlier..