The add-on simply stopped working few days ago. No instructions whatsoever on how to recover tabs on a Linux machine of course... In short: all the tabs lost!

EDIT: Changed from 1 star to 5 stars
The add-on is working again, and all the old data reappeared. I guess problems happen, the important thing is that they are solved promptly, and this is the case!

This is one of my all time favourite addons, so it was with horror and dismay, after it having worked without a hitch since the day I installed it, I awoke one day to a totally blank OneTab page staring back at me with terse and cold indifference. The "OMFG, no, no, no, no, NO, this can't be happening!!" factor was real!!

But! Having regularly taken advantage of the backup option, I was somewhat hopeful I could fix things and lose only a couple of days worth of new tabs. Unfortunately though, no amount of disabling/re-enabling or uninstalling/re-installing could bring back the last tabbed days of my online life. Then, having nothing to lose, I decided to revert to an older version as suggested by a user further down the comment line:

https://addons.mozilla.org/firefox/downloads/file/3359470/onetab-1.29-an+fx.xpi

Oh blessed be!! It's back! It's all back! I could hardly believe it! Whew! Cheers of joy, high fiving myself (and the cat) and a couple of woop woops broke the tense and mournful atmosphere and I was back in business, baby! :) (Shout out to Keegan Witt for the link to the old version. Thank you, my friend! Thank you!)

So... Despite the heart attack-inducing shock of potentially having lost all that was dear to me (tab-wise anyway) I am giving this addon 4 stars. When it works, it works like a dream, so I won't punish the team who made this otherwise brilliant addon by giving a lower score, because do you know what? Sometimes, shit happens. Yup, sometimes it just happens, even to the best of us. The fatal errors in the new version are most certainly not done intentionally and I feel a great deal of compassion and empathy for the poor developer/s who are maybe having a minor heart attack of their own, sleepless nights and they're probably (hopefully) working feverishly in a panicked sweat to fix whatever went wrong and get things back on track. I just can't bring myself to jump on any "cancel culture" bandwagon and diss or abandon this addon after all it has done for me, and besides, I am hopeful there'll be fix soon.

So, to keep this review short, (Yikes! Too late!) I still request a donate button somewhere on the OneTab page and I will be thankful and grateful and happy for having this FREE addon available to me. When it works, it's a little piece of heaven.

So as I said, 4 stars it is, and now I'll be off. I have some more tab-hoarding to do....

Rant over.

Edit (a couple of days later): I'm upgrading my rating to five stars. Turns out all the blame for the temporary malfunctioning of the addon lies with Mozilla and not the OneTab addon. Installed the latest fix and everything's back in perfect working order.

Excellent extension. You can save your open tabs, rename the group share and save. I find it really useful.

[I am changing my rating from 4 to 5 stars, since the Firefox bug has been fixed.] I "can't live without" OneTab, as it's THE daily tool I use for tab management. LOVE the simplicity & functionality! Way better than bookmarking tons of pages I'm reading/researching but may not want to keep later. BUG NOTE: Reviewers who still have problems with the bug simply need to update their Firefox browser. (Even if you don't, the work-around on old browser is very easy. We didn't LOSE our old links like some have reported, though it was very upsetting when it seemed like we did.)

This add-on is working perfectly once again. After a slight glitch, everything works as it should. One of my fave add-ons, as it reduces tab clutter instantly! Highly recommended.

Edit: Developer fixed the issue and quickly responded to my review. It was an unfortunate bug but I am happy with their fast updates and customer service.

Great add-on but the last update broke it. I need to disable and enable it to get the add-on to work

It's a very good tool for saving the state of your tabs and then go back to them ,when you need. Very useful for IT jugglers.

For all of you who have problems after the September 16 update, I guess the solution is disable and re-enable it. No idea why it broke after the sept 16 update but it seems to a viable solution. Otherwise, OneTab is a wonderful extension that does exactly what it says. It's one of my most used extensions. Hopefull the OneTab team could help fix this issue.

For those who lost their data:
Just close and restart the addon.
(You don't even need to close Firefox.)

I've been using One Tab for a while, and I love it!! After the update on 16 Sept however, I opened my computer to find all the sites listed on my One Tab had disappeared, and the icon wasn't showing properly on the toolbar.
GOOD NEWS!! After I read some reviews, saying they disabled the add-on, restarted, then enabled it again, everything was restored!! Yayyyyyy!!
5 Stars!! ⭐⭐⭐⭐⭐
To all those users who had the same problem and bagged it out in a review, I suggest you try the above fix, and then change your review!! 😊

Superb addon. But after update it stopped working. I disabled it, restarted Firefox, then enabled it. So everything fine again!

Con la última actualizacion de septiembre, se atenuó el icono y no funciona. La solucion es desactivar la extensión, cerrar el navegador y al volverlo abrir aparece todo de nuevo. Años usandola y es perfecta esta extensión.

This is a great tool. With the updates mid Sept. 2020 its toolbar icon grayed out and the saved tabs was blank. Some people uninstalled and reinstalled and said they lost the links. Instead of that I disabled it, restarted Firefox, and re-enabled, and restarted Firefox - the icon and links were all back.

Awesome, I love this addon 😍

As far as the latest update, it basically removed the add-on from Firefox. I followed what Justin said from another review, but for Mac OS : /Library/Application Support/Firefox/Profiles/08nnu9pm.default/extensions > open "Extension@one-tab.com.xpi" with the Firefox application, it'll ask you to reinstall. Now the add-on will be back, and running normal.

發生什麼災難了？在重開 fx 後，記錄下來的網址全沒了……天啊啊啊啊
--- after bugfix
資料回來了！辛苦了！改回五顆星！

UPDATE:
I am updating again to 5 stars in good faith that the developer has fixed the issue. This really is a great add-on.

Original Review:
Loved this add-on until yesterday. Everything disappeared (page with my links, icon). From reading other reviews it appears that it will work again if I uninstall/re-install add-on, but big bummer to lose my tabs. I got to rely on it a little too much. Now I will know that it is much more of a temporary holding pen.