I occasionally get this from some sites. Sometimes switch to safari or reset Firefox fixes it. I use Firefox as a quick lookup because the tabs crash often and

I occasionally get this from some sites. Sometimes switch to safari or reset Firefox fixes it. I use Firefox as a quick lookup because the tabs crash often and it hardly ever saves the websites I was on when re-opening. So far I have crashed safari and lost all my tabs once ever. Firefox focus does a pretty good job too for quick lookups.