Great addon. One option I would like to see is possibility to be asked if previous session should be restored, like in good old Tab Mix Plus. Currently there is option to restore previous session on startup, without asking.

Works great! Would love the option to merge windows when restoring sessions =)

Till Now, I had no problems, but today, 13 July 2019, this extension seems to have some problems with syncronisation of SOME tabs. Indeed, some of my tabs cannot be loaded and I cannot see what was in these tabs since they are empty now. Please correct these bugs, maybe due to a Firefox update. Thanks in advance. Eric from France.
UPDATE, 15 July 2019 : PROBLEM SOLVED, THANKS !

Hi, I had an indexDB failure [after updating to FF 68], tried the Github 'Internal UUID copy-paste folder trick', didn't work; seems TSM's own json got corrupted, so I lost alll my sessions.
Please would you consider using eg Bookmarks [like MySessions] instead of indexDB that is so prone to corruptions?
Other than that, great addon, thanks.

Dobry dodatek. Brakuje tylko jakiejś synchronizacji między komputerami. Wtedy niewątpliwie 5.

Supernützliches Addon.
HINWEIS: Wenn das Addon nicht funktioniert, wenn es nicht speichert:
Geht in die EInstellungen des Addons (über ADDON) und löscht alle Sitzungen. Danach funktioniert es wieder.

NOTE: If Addon not works or not Save Sessions:
Go to Settings of Addon (over Firefox ADDON Menu) and delete old Session Manger Sessions. After this, Addon works normaly

Спасибо, отлично работает.
Также спасибо за поддержку Tree style tabs.