After installing the Microsoft fall creators 1709 update, Firefox crashes about 20 seconds AFTER I close it. when I close Firefox, it closes but it is still listed in Task Manager, not as a running App but as a "Background process." If I do not highlight it and click "End Task" in Task Manager, in other words do nothing, the Firefox crash reporter pops up after about 20 seconds and says Firefox has crashed. It also does this in safe mode. I've tried everything to fix it, including doing a system file check and reinstalling Firefox but nothing has fixed this. I am sure you are aware of the problem and hopefully we will get a fix in your next Firefox update, or be informed of a way to fix it. Thank you.