Robin
Hi @Stevesr0, has firefox been upgraded recently on your system?
This smells like an incompatibility to a new version of the settings mozilla stores in your home folder; In this case firefox decides on its own to create a new profile for you, which explains why all your former settings were gone. Check the hidden .Mozilla folder in your home for the old profile. You may be able to revive it once you have downgraded to the former firefox version manually on which this profile has been flawlessly used last.
Windows is like a submarine. Open a window and serious problems will start.