why can't i open facebook?

Hi, assuming this is only happening on FB; try deleting ALL references to FB. To do that, open the 3-bar menu, choose History (looks like a clock), then click the Show All History link at the bottom of the list to open the Library window. Type '''Facebook '''in the Search History field in the top-right corner, then press Enter. Now in the search results, right-click on FB, and select Forget About This Site. (Browsing and download history, cookies, cache, active logins, passwords, saved form data, exceptions for cookies, images and pop-ups for that site will be removed). Give it a minute to complete the deletion then try the site (not from an old bookmark) again. More - [[Delete browsing, search and download history on Firefox]] ''If your question is resolved by this or another answer, please take a minute to let us know. Thank you!''