Downloaded the latest Firefox update a couple of days ago and it fails to complete installation, and gives the failure message each time I restart and implying that another copy of Firefox is running.
Not too worried, it still works OK, just annoying though.
Might be worth uninstalling it as per Mozilla instructions and then reinstalling.
https://support.mozilla.org/en-US/kb/uninstall-firefox-from-your-computer (https://support.mozilla.org/en-US/kb/uninstall-firefox-from-your-computer)
Good luck
:beers: