''[Locked as a duplicate of https://support.mozilla.org/en-US/questions/1224641. Please follow up there, thanks.]'' I already submitted this but never got a confirmation that it was sent so its a duplicate, delete if the other one appears. This is a recurrent problem when Firefox is left open a day or two and many tabs are cycled in that time. When closing Firefox it crashes and all new bookmarks are lost which is the most frustrating part. Before it happens no new bookmarks can be added and when its at this point bookmarks cannot be backed up before the close/subsequent crash, when i try it does nothing. This has been happening the last few versions of Firefox I have submitted this many times under the same e-mail as this account in the crash reporter Please get back to me if there is more information available or a solution is found