Hello aerocell, 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:
Go to Firefox > History > Clear recent history or (if no Firefox button is shown) go to Tools > Clear recent history.
Under "Time range to clear", select "Everything".
Now, click the arrow next to Details to toggle the Details list active.
From the details list, check Cache and Cookies and uncheck everything else.
Did this fix your problems? Please report back to us!
if the above does not solve the issue try to delete the cookies.sqlite file and any cookies.sqlite-journal files in profile folder in case you may have a corrupt cookies file, see how to do that: Remove corrupt cookies file