Seems like IndexedDB was updated in Firefox v74. This addon stores sessions in IndexedDB. And old DB files don't work with new version. That's why we have errors like "IndexedDB error" or instantly closing Tab Session Manager window. Sessions are stored in Firefox Profiles foler. If you backup them and reinstall the addon it will start working fine. To recover them you need to install old version of Firefox somewhere, install Tab Session Manager, add backuped sessions to it (google for instructions by sienori on github) and export it to .sessions (JSON) format. Then you'll be able to import them to freshly installed Tab Session Manager in Firefox v74.

It would be nice to be able to edit tags or make tags case insensitive. Sync would be great too. Tab Session Manager has evolved a lot. Great usability changes, keep it going!

It does what it says, and I like having this long history of my sessions that I can go back. Makes me feel safe about accidental closing windows or crashes.

There is one huge caveat that makes it pretty much unusable for me, is that restoring session will loose the container tabs and will reopen everything in the default container which is a no go for me :(

A very handy add-on for your firefox browser

I just added it and it makes my life better! Great way to save multi-window sessions.

Seems ok, but does not restore sessions with local files such as PDF's. This may be a limitation outside of the developers control, but makes the extension useless for me.

Hello sienori, thanks for that nice extension. I like it very much, it works very good so far.
Only some features I am still missing:
-Edit: I found it ;-) its under settings / sessions = import older session
- an option to define a limit number for automated saved files which are generated in Backup folder - so that older ones will be deleted "automatically". Or at least user limit number and get a message popup when the limit is reached so everyone knows to start cleaning autdated saves.

Thanks in Advance an greets from Germany

And: plus an option to name automated saves user defined like "Autosave", because the title of the tab currently active is not very unique, the same with saved when "browser closed" or when "windows closed", so we can distinguish better between them.

very helpful! has a lot of options, like this addon a lot.