''locking this thread as duplicate, please continue at [https://support.mozilla.org/en-US/questions/1054971 /questions/1054971]'' I just updated to the new firefox and all of my sessions are now blank or possibly corrupted and it only says how many tabs i have in each session ,but i cannot click on "recover session". Can i roll back the 36 version ,or is it a problem with session manager not being compatible with the new version ? How can i recover my previous session at least?