Good evening Sen, I'm Shred, Sorry to hear that Firefox keeps crashing. Seems odd to me that it would crash with a 18.04 LTS and vanilla Firefox 83.0. Cause I happen to use Ubuntu 20.10 with a custom kernel (5.9.0-14.1-liquorix-amd64) and Firefox 83.0. (several plug-ins) never crashes, only Youtube Video's won't buffer properly from time to time (once a day). I simply suspend or log out and back in and it works just fine (I can live with it). Have you tried to post a question on the Ubuntu forums? To me there seems to be a problem within your Ubuntu system cause the system rejects the request from Firefox to write and/or edit files (anyone correct me if I'm wrong). Just happened to come across these articles on the Ubuntu forums: https://askubuntu.com/search?page=1&tab=Relevance&q=firefox%20crash%20ubuntu%2018.04 https://askubuntu.com/questions/1227398/firefox-keeps-crashing-on-ubuntu-18-04-4 https://askubuntu.com/questions/1223691/ubuntu-18-04-crashing-even-after-clean-reinstall-of-os For now I would suggest to upgrade to Ubuntu 20.10 with the Custom kernel. Cause I'm still learning to troubleshoot Ubuntu logs take some of the above with a grain of salt. If the above does not help then I'm not capable to help you any further, my sincere apologies.