This addon saved my life :D Stupid Mac has updated and closed my Firefox, which for whatever reason has lost my session afterwards, and the sync of tabs from Mac - again, for some bloody unknown reason - was completely lost from the list of the devices I use (this is, I believe, Firefox's own fault)!

I was already devastated because Firefox inexcusably dropped support for two biggest life-saving add-ons - Session Manager and Lazarus, and was regularly checking if they will be re-enabled until recently, when I gave up and just started considering completely switching to Chrome. (Meanwhile I have found Cyberfox which is like an older Firefox version which supported these add-ons :D )

I went to check the add-on market (which had only one extension compatible with Firefox Quantum, and of low rating), and found out that a few more have popped, and decided to install this one - I was so happy when I found out that it supports Session Manager's session backup files and that it actually worked! It wasn't the latest session, albeit (because I had no means of saving it!), but still recent enough so that I got back my tabs for learning stuff.

If there is any decent replacement for Session Manager, it is MySessions. Thank you!