Some may claim that Firefox has grown into a hard to tame beast.
Problems can occur with your profile folder, but you do not have to waste time identifying and fixing the exact cause.
As you probably know, out of date programs can give hackers an easy way to gain access to a PC.
One of the programs I needed to update was Adobe Acrobat Reader.
You can also enter Safe Mode by holding the Shift key while starting Firefox.
Try using Safe Mode for a while if Firefox is crashing.