''qqqfox [[#question-1113580|said]]'' <blockquote> Lost all my firefox open tabs & windows when I did your latest update. Sync won't work now either. _{edit: removed your mail address from public display, since the only thing it will attract are spam bots. you will be notified per mail once somebody replies to the thread. (philipp)} </blockquote> Hello, have you tried a Firefox Refresh yet ? https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings There is a possibility these things are lost but we will try to help. I am not a Sync user so someone will help you on that. It would be good to try above option as it will be asked for you to do if not already done. Suggest also try Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) to see if that has effect and disable add-ons/plugins from there also so that when reboot can tell if is a add-ons/plugins issue if problem persists. http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/ G'luck