Tab Session Manager has been working largely without problems for years.
However, since April 6, automatic saving is no longer carried out, neither automatic saving, nor regularly saving the session, nor saving the session when the browser or window is closed.
There are approx. 1800 open tabs

On two different ff versions 91.9.1 and 115.20 it randomly deleted ALL sessions, on one ff i lost a sessionwith 2000 tabs and on the other 1800 tabs, backup is disabled by default, no other backups are kept and recovery is possible only if you have all your history from the past 6 months. evrything else is pretty good.

used to work but recently after the notorious Firefox update it's now broken and author does not respond.

After several months of using I can say: Absolutely Vital. When you don't want to close a window (just in case you possibly would miss the tabs), save the window instead. No more gazillions of windows, and no tab is lost.

works

Was very good. Now completely unusable only on Firefox as it ungroups Tab Groups despite having support for it

das beste Addon zu Sessionverwaltung in Firefox und Opera Web Browser!! Benutze es seit mehreren Jahren in Firefox und nun auch in Opera - absolut zuverlässig und unglaublich simpel zu bedienen.

Doesnt store protected/muted/etc status pages=\

完全に動作します。仮に将来動かなくなっても無料の物に理不尽なクレーム付けるほど人間腐ってません。今後とも感謝しながら使わせていただきます。