I've used Firefox for Mac for decades without any problems. When I upgraded the Mac OS to Big Sur a few weeks ago, my Mac started crashing frequently, several times a day, sometimes within seconds. After numerous trials, I discovered that the cause was Firefox. If I remove Firefox (along with all the profile information) and use Safari instead, the Mac never crashes. If I download a fresh copy of Firefox and start using it, the mac crashes within hours. Does anybody know why the latest version of Firefox does not work on Big Sur? Is there a remedy coming? Safari is okay, but I really miss Firefox, and I would like to go back if the problem can be fixed. Thank you. L. M.