It used to work fine on Firefox mac, now nothing happens when you click OPEN or OPEN IN NEW WINDOW.

Hopefully, it will get fixed soon.

Fundamentally useless. 'Open' button for saved tabs cannot be coaxed to work, at all. F$^# this piece of s#$^%.

It prevents the device from receiving tabs that were shared with it... other than that, I like it, but that feature is more important than this add-on.

It's highly customizable, and it works exactly as I want it to.

Works well for me so far.
Please add support for local PDFs, so they can be reopened when restarting the browser.

I am a paid user of other browsers. I tried the Firefox version, but I encountered a few frustrating points. For example, when restoring a session at startup, the window shifts slightly to the left. It would also be nice if it supported title-changing extensions like Window Titler, but this might be unavoidable until Firefox officially supports it.

I hope for future improvements!

Almost does the job, but tab groups are destroyed, as others have mentioned.

Firefox closed all my tabs without warning and couldn't restore them from its own session backup files, even though those files contained all my tabs. This extension helped me restore them all easily, which saved me from having to restore a large number of tabs manually, one by one.
If this extension wasn't there, I would have replaced Firefox with another browser.

Once every few months, it randomly dedices to delete all my sessions and reset my settings. Absolute trash.

This extension used to be great! I donated a few times. Today I had to force restart my computer and Firefox came up with no tabs! I checked the Tab Session Manager and the last save it had was from over a year ago! I guess the auto save doesn't work any more and all the sessions I did have saved are gone. This extension is totally broken now.

STILL DEAD!

Did not save the "tree" from "tree stile tabs", and I did make sure to have "Restore tree state of Tree Style Tab." checked.

All pin and save tabs lost. I removed this scrap

Unlike the session restore built into Firefox, this add-on does not retain or associate an individual tab's browsing history when a new browser session is launched. I use this quite a lot, so I may look for a different add-on which does support this.

Would've rated it higher had the manual export setting functionality included the sessions I had saved.

Doesn't save tab groups. Also says it supports importing JSON files from Session Buddy, but it does no such thing. It gives me a read failed error.

Used to be one of my absolute favourite extensions, but since stopped working as intended. It does save my browser windows, but I can't restore them except for clicking and restoring every tab single-handedly.

It has saved me several times when I've closed windows with at least 500 tabs that I don't want to lose this makes sure i can take my time to go through them.

Also why is this not standard with firefox?

The delete button is very close to open button and because of that, some time I clicked on wrong button to delete instead of open. It would be better if you add confirm dialog before do delete the session (even you already had undo but it will be better to ask for confirmation on delete).

I had around 500 tabs open that failed to get restored beyond the first 10 when I shut Firefox down, which hadn't happened before. This extension brought them all back which saved me quite the headache. Of course, it couldn't bring back the groups from Tree Style Tab, but it was unrealistic to expect it to save another extension's data.