I've had 4 different Firefox windows for months now or even more than a year. I use two monitors and I use lots of tabs. It has been easier for me until now to organize like that. I have 3 Firefox windows on my main monitor - one of them has like 10 tabs open. The other has 5. And the third one had maybe around 100. On the other monitor I have the last 4th Firefox window that has around 500 tabs open. I do this all the time where I get to a point in which I review them all in a day or two, filtrate thru the content I saved thru this method and after that reset the browser. So today I started this cleaning process with the 3rd window that had over 100 tabs. Was going great when suddenly I clicked the X button on the whole window and without any warning it instantly closed. I restarted the computer and nothing happened. All my information from over 100 tabs now gone forever and honestly this might sound funny to you but I'm literally having a panic attack right now having difficulties breathing. Before when it happened at times that I click the close button on these windows it always asked me a warning message if I want to close the window with these X tabs. No matter if the tabs are 10, 100 or 800. Always. No matter how many windows I have opened with different tabs in them. I immediately checked my settings and I see that "Confirm before closing multiple tabs" wasn't turned on which like NO WAY IN HELL did I go in the settings menu and turned that thing off. I haven't been in the settings menu since I installed firefox on this PC which was after I got my Windows OS like 2 years ago. And as I said I remember multiple times in these past months where I clicked the close button and it asks me if I want to close these X multiple tabs. So I dunno how that happened. Also I had the "Open previous windows and tabs" TURNED ON but that also didn't work apparently for some reason. So I'm not really sure what question I want to ask here, I guess I want some explanation why these things happened when clearly they shouldn't have and it wasn't my fault/mistake (from my point of view considering the facts). And also if there is any way to restore that window with the closed tabs.