Firefox foul ups

[Steve Underwood]

Is anyone else having problems with Firefox on FC39 with XFCE recently? 
After rock solid operation for a long time, in the last 2 or 3 weeks the 
UI has been fouling up every day or two when I do some seemingly mundane 
operation in Firefox. A couple of times Firefox has crashed after a few 
seconds. The foul ups sometimes only affect the Firefox windows, and 
other windows still work OK. Sometimes the whole desktop fouls up, and I 
have to switch to a text only screen and kill Firefox. That restores 
normal desktop operation for all the other windows.

Steve