This is more about feedback rather than a question. I am unable to find a place to post feedback here, let me know if there is a better place to post this. I want to direct this to the developers, but would also welcome discussion from other users. '''Background''' I am a user that usually keeps a lot of tabs and windows open. It is important to me that this is restored from last session when starting firefox. When closing firefox with more windows than it will remember then the excess windows will be discarded without any warnings. Default seems to be 3 from about:config '''Short term solution''' I think users should get a very clear message when closing firefox that it will be unable to restore the complete session later on restart. I believe this behavior is unexpected for all or most users. '''Better solution''' The much better option here is to NOT discard session history for windows on close. ALL windows closed should be reopened without any hidden limitations inside about:config If i didn't have any very specific order in which i opened my windows then it means that the order was random, in which case firefox is discarding windows at random for later restart. '''about:config lost on update?''' https://chantheacce71.blogspot.com/2022/03/why-does-mozilla-firefox-keeps-losing.html > When i update firefox then part of this history seems to get lost. It's hard to recreate or to find reliable sources on this but it seems like about:config may be reset on firefox update. In which case the value is going back to 3 and all excess windows are lost even if i increased the value earlier. I recently experienced this, and it's not the first time. If the solutions above are not used then it would be good if firefox could avoid resetting this value as the result can be disastrous. Last time i was unable to get my window history back. i checked my sessionstore-backups and it was not there.