I normally have a few tabs open all the time. When I close FF with the windows x on the title bar it closes and when I click the FF logo pinned on the taskbar FF opens with my previous session tabs, this is normal way work. Then for some reason it suddenly changes so when I open FF I get a new window with no tabs. I usually can recover this with >History>Recently closed tabs. But if FF is started with a link in a document, I deal with that and when it closes I realise that it had opened a new window, when it closes there is no recently closed tabs history and I've lost them all. I think this happens because the link opened a new window and closed it automatically and now because it had no more tabs open there is no tab history to recover. But then it stays like that. Every time I open FF it opens a new blank window, I click the >Recently closed tabs and get it back. Then close the new blank window then close FF but it doesn't re-open with the previous tabs even though it's set to do so. It works OK for a while and then suddenly starts this aberration. I've tried getting help on this before and was advised to close FF >3Bars>Exit but that closes all open sessions rather than just the one I want to close. This problem has been on going for a long time and is extremely annoying when all the tabs are lost. I even suggested that there could be a session stack maybe 10 or 20 so we could open that and recover any of the stack sessions we wanted. I'm sorry to say that FF is not the reliable browser it once was.