Fairly regular crash, unable to restart (even in safe-mode) post-crash without reboot
I'm experiencing relatively frequent crashes of Firefox under Ubuntu Focal (approximately daily). The rather frustrating aspect is that, after the crash, Firefox immediately crashes when attempting to restart (either from the crash reporter dialog, or separately after quitting and attempting to launch it again). Re-launching in safe-mode also crashes immediately. However, after rebooting the machine, Firefox is absolutely fine once more (until the next time) which suggests to me there's "some state" left lying around somewhere preventing the restart (and perhaps related to the crash itself).
Here's the IDs of a couple of the safe-mode crashes, from attempted restarts (I figure those are most useful in cutting out the potential cruft; for reference, the non-safe-mode crashes appear to be at the exact same location):
Nothing comes up in the Correlations section of the report, and a search of the signature doesn't seem to turn up much relevant. Frankly, if I could just figure out how to get the browser restarted without rebooting the whole machine, that'd be a big step forward for me :)
Many thanks for any attention people can give this,