Many site issues can be caused by corrupt cookies or cache. In order to try to fix these problems, the first step is to clear both cookies and the cache. Note: This will temporarily log you out of all sites you're logged in to. To clear cache and cookies do the following:

1. Go to Firefox > History > Clear recent history or (if no Firefox button is shown) go to Tools > Clear recent history.
2. Under "Time range to clear", select "Everything".
3. Now, click the arrow next to Details to toggle the Details list active.
4. From the details list, check Cache and Cookies and uncheck everything else.
5. Now click the Clear now button.

Further information can be found in the Clear your cache, history and other personal information in Firefox article.

Did this fix your problems? Please report back to us!

I was aware of this fix. I have done this successfully and the result was as expected: a return to normal. BUT... this has happened several times just in the last few days since I switched back to Firefox from IE and I close everything, clear cache, back to normal.......and the reason I went to IE in the first place was because of this exact problem. Are there no preventative steps??

Hello netpaid, also, if you don't already do, try to delete the cookies.sqlite file and any cookies.sqlite-journal files in profile folder(in case cookies are corrupted), see how to do that : Remove corrupt cookies file

thank you

You can't attach a screenshot to the first post that starts a thread, but you can do that in subsequent replies.

Which security software (firewall, anti-virus) do you have?

Make sure that your security software isn't blocking (CSS) files.

Try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that helps.

Ok so it's happened again. I have attached screen shots of my FB page and also another website I tried to open. Before I clear my cache again, or delete corrupt cookies files (I doubt that would ne the problem since FF seems to work fine for awhile - a few hours, a few days - and then crashes upon opening a new tab.

I am using Windows Defender and Windows Firewall.

I would love to move away from Windows entirely; to Ubunto possible, but the time and talent for this I do not have.

Sorry... a few more screenshots here