Firefox Community Forum

Firefox prompted me to update, I hit download, my entire PC froze, I restarted the computer, when I opened firefox again and hit "restore session" it restored a session that I had opened months ago. When I checked my history, everything after that older session had been deleted. All of my history from the past few months has been deleted. I tried a few different solutions from trying to research the problem, nothing so far has worked. The only thing I have found is a session restore error saying "could not decompress file", but I could not find the file it was attempting to decompress. This is the error message I found.

1785894397652 SessionStore ERROR NotReadableError when reading session file: recovery: NotReadableError: Could not read `C:\Users\ansen\AppData\Roaming\Mozilla\Firefox\Profiles\xpnhovd6.default-release\sessionstore-backups\recovery.jsonlz4': could not decompress file: invalid LZ4 header: wrong magic number: `00 00 00 00 00 00 00 00 00 00 00 00' (NS_ERROR_FILE_CORRUPTED) No traceback available 1785894397756 SessionStore ERROR NotReadableError when reading session file: recoveryBackup: NotReadableError: Could not read `C:\Users\ansen\AppData\Roaming\Mozilla\Firefox\Profiles\xpnhovd6.default-release\sessionstore-backups\recovery.baklz4': could not decompress file: invalid LZ4 header: wrong magic number: `00 00 00 00 00 00 00 00 00 00 00 00' (NS_ERROR_FILE_CORRUPTED) No traceback available

Any help is greatly appreciated. I'm one of those people that tends to have way too many tabs open at once due to poor memory, and losing months of tabs and progress is a huge setback. I'm very desperate to get the history and tabs back.

ich benötige die übermittlung, da das chronic dieses eingestellt hatte: die auffindung der www´s durch das vorgehen bei dem umstellen der mozilla-umsetzung bei der neuinstallation. durch dieses hatte ich die www von einer bestimmten auffindung nicht (ich kann die www gern durchgeben: frau, bdsm, in der nähe, aber ohne kommerziellem hintergrund !).

My Firefox crashed when my laptop was inactive. When relaunching it didn't have my usual tabs open so I did the usual, history- restore tabs. This didn't work and only opened 2 tabs when I know I had about at least 15 open. Please tell me other ways I can do this? they are backed up in file library, how do I restore them from there? or any other way, this is frustrating.

Thanks

gerald.r.vargas 4. Aug. 2026, 08:23 GMT-6 Hi, this morning for some reason all the tabs I had open couldn't been loaded. Refreshening the page didn't help either. So I decided to shut down and restart my laptop.

Unfortunately after restarting Firefox only one page and its tabs have been reloaded.  All the others were gone. 

After trying about:support and session:restore it didn't help either, because only the 4th of Aug. was available. Is there a possibility for a session restore from the 03rd of Aug? or the previous days? If anybody has an idea, how to do so, please let me know.

Many thanks, Gerald R. Vargas

This is a recurrent problem. I'm online with many tabs open, when all of a sudden they disappear and when I try to recover them by going in "history" [using the three lines at the top right of screen], and then selecting "recently closed tabs", and then try the "restore tabs", nothing happens! Previously, this had worked to offer me a way to reopen those tabs one-by-one, but now it doesn't restore anything. ALSO, I used to be able to shut down my computer, wait a few minutes, and then restart it, and would be offered a "restore session" option when the computer restarted, but that didn't happen today even after trying this twice.

I was once shown how to restore tabs by going up to the top right of the screen, but cannot remember how to do this. Can you please help me from loosing tabs, and my mind? Thanks.

Hello! I am having trouble restoring my old Firefox profile after migrating my system from Windows 10 to Linux (Fedora). I have a backup file in .html format that is 197 MB in size (originally created on Windows). When I try to select and restore it using Firefox's built-in recovery tool, it throws an error: "Something is wrong with this file. Please try again with a different file." What I have tried (and what didn't work): Moved the file from an external drive to the local Linux Downloads folder (the error persists). Tried dragging and dropping the file directly into Firefox (the recovery page loads, but the restore buttons are missing or inactive due to security/script restrictions). Tried renaming the file extension from .html to .zip to extract its contents manually, but the archiver threw a "Not a zip archive" error. The built-in recovery script fails to process a 197 MB HTML file, likely due to size limits or memory handling on local files. Could you please advise on how to properly handle and restore such a large backup file or extract my data (passwords, history, bookmarks) from it on Linux? Thank you in advance!