Firefox is suddenly and randomly shutting down for me as well.
Firefox just shuts down and when you reopen it the result is as others have reported - it lists the tabs that were open and you have to wait for the pages to rewrite. Some revert back to a log in screen but most go back to the screen when Firefox shuts down. There are no issues that are evident and nothing comes up in the alerts on my AV, etc. programs. It is really annoying when you have just logged into a mail program e. g. hotmail; aim; and it is in the private browser screen. This one does not reopen and you have to start from the beginning again. It has only been happening over the last week or so and can happen 2 or 3 times in a day, depending on how long the computer is being used - extended day or just a short few hours. There are no crash reports or error messages from Firefox. It just totally shuts down.
This problem continues to occur at inopportune times. Firefox has been completely uninstalled and then reinstalled from a new download. Doesn't happen on macbook. This happens on Windows 10 desktop (with latest updates). No responses since Nov 02! I noted when I posted this others were having similar issues. Have fully checked system for malware, virus, etc. Happens over a variety of sites including speed test, email - hotmail, yahoo, etc. Maybe I need to change to a different browser?? Have used Firefox for a very long time and not had issues in past. Frustrated.
Unfortunately this issue continues in the latest update released. Will Mozilla / Firefox for Windows be fixed or do I change browsers? Have used Firefox for years and am now disappointed as this continues to happen. No responses to my original question or the follow up. This one...... We will see.
It continues and is becoming more frequent - so far today 3 times! Still ZERO response from anyone!