Using firefox 144 on Kubuntu 24 LTS, on wayland, with Nvidia drivers. I'm one of those guys with 500+ tabs. I also have a bunch of tabs open in specific containers and I recently spent a lot of time sorting most of my hundreds of tabs into a bunch of neat tab groups. I'm not using any "sync between devices" functionnality At some point, I open firefox like usual, and I noticed that it appears to be glitched. The rightmost tab (the last tab I had opened) seems to be working fine, but every other tab has no text, and I cannot switch to them. However, the colored line indicating that a tab is opened in a specific container still appears, it's just the tabs names that are missing. Also, firefox seems to generally not be responding, so I decide to close and reopen it. Upon reopening, firefox restores my tabs, but I'm left with only the last tab I mentionned earlier. The "restore last session" button doesn't appear in "history". Neither "recently closed windows" nor "recently closed tabs" contain my 500+ tabs I still have my extensions I still have my bookmarks I still have my base "new tab" setup, with my background image and my "pinned" websites (I don't know how it's called) I still have my container "rules" (i.e, firefox still proposes to open specific domains with specific containers, even if I have lost old tabs that were opened in those containers) I still have my "auto sign-ins" (i.e, I can still log into some websites without re-typing my password) I have lost my tab groups I'm used to losing my tabs. So I close firefox, and I go look in it's files. The image firefox-mpris in the files still displays a youtube tab I was watching (yet this tab doesn't get restored) I make a copy of sessionstore.jsonlz4 and sessionstore-backup, and try restoring from each backup by replacing sessionstore.jsonlz4 : - the default sessionstore.jsonlz4 doesn't have my tabs of course - previous.jsonlz4 has only the single last tab I mentionned earlier. - recovery.jsonlz4 contains only 20-ish of some of the most recent tabs I had - the "upgrade" files contains a bunch of tabs but it's from a few months ago so I'm missing the most recent stuff Using this "scrounger" tool, I can look at what these files contain https://www.jeffersonscher.com/ffu/scrounger.html - sessionstore.jsonlz4 and previous.jsonlz4 both contain the single tab we talked about before (plus closed windows I don't care about) - recovery.jsonlz4 contains exactly 25 recently opened tabs (plus closed windows I don't care about) - upgrade.jsonlz4 contains 500+ tabs (with container ids, yay), but not the most recent ones of course (plus closed windows I don't care about) From I saw online it looks like firefox only stores the last 25 tabs in these files, which are the last tabs I actually opened, even if more actually exist. What I really don't understand is : - Why does my upgrade.jsonlz4 file have more than 25 tabs then ? - Where are the other tabs supposed to be stored then ? the .jsonlz4 stores the last 25 tabs, yet firefox (usually) remembers all my 500+ tabs anyway, so where are they stored ? Also, y'know, pls help me restore my stuff. Thanks.