@penguingeek No such luck, just crashes immediately, with new profile, after update, after reboot, after re-install, after removing ~/.cache/mozilla and ~/.mozilla. Doesn’t work with firefox -safe-mode. Anything I do gives:

$ firefox -safe-modeExceptionHandler::GenerateDump cloned child 5885ExceptionHandler::SendContinueSignalToChild sent continue signal to childExceptionHandler::WaitForContinueSignal waiting for continue signal...

I also tried running VAAPI_MPEG4_ENABLED=0 firefox. Crash on startup. Super weird.