Is it just your add-ons? What about everything else? Settings, history, passwords . . . . .

Yep. Just add-ons. Everything else, bookmarks, settings, etc... remain the same, just the add-ons disappear.

In order to prevent a possible long way of troubleshooting, it may be good to perform a clean reinstall of Firefox as suggested in this similar support question. Be sure to create a new profile as part of the process.

I would do so myself, or rather, back up the current profile, uninstall the current Firefox version, then deliberately reinstall Firefox 53 or any older version (start here) to check what happens as soon as you let it update to 54. You may not suffer the exact same issue, but it will do no harm.

Well, it is certainly worth a shot, because it really doesn't seem like this is normal. I also forgot to mention, any time I do a RESET of FF all the add-ons are gone too... I will post what the results are.

As this is just the add-ons;

It’s possible that there is a problem with the file(s) that store the extensions registry.

Type about:support in the address bar and press enter.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Delete all extensions files and compatibility.ini in the Firefox profile folder to reset the extensions registry.

• https://support.mozilla.org/kb/Profiles

New files will be created when required.

After, restart Firefox.

See "Corrupt extension files":

• http://kb.mozillazine.org/Unable_to_install_themes_or_extensions
• https://support.mozilla.org/kb/Unable+to+install+add-ons

+++++++++++++++++++++++++++ You will have to approve the updating one last time.

Well, I already did the reinstall FredMcD, but I will try what you are suggesting if things aren't fixed... Funnily enough, I downloaded the last FF 53 version and instead of updating to 54 it updated to a beta version of 55... Not sure how that happened, because I did not even manually have it check for updates or anything. It did reload all of my prefs, add-ons and bookmarks from my profile, which I was happy to see so... We'll just have to see now if add-ons stay loaded, etc...

Thanks for the help Tonnes!

And so it has done it again. Really pissing me off.... All of my stupid add-ons are gone again after updating FF to version 57.whatever.... So sick and tired of this garbage. Shouldn't have to deal with this. I am signed into my FF account and the stupid thing did not restore my add-ons AGAIN! Really wish someone from Mozilla would chime in and answer my gd questions about this...

Stab in the dark, but do you by any chance have the 'Session Manager' installed  ? Some other user mentioned that this add-on turned out to be the culprit .....

And I did try what you suggested FredMcD and it did not work. Now, it could have everything to do with the add-ons that I had installed not being compatible with FF 57. xxx and I am not sure which ones I had installed, since there is no history anywhere of the ones I had installed, which is frustrating too.... You'd think, since I was signed in to my FF account when I added them last time, there would be some kind of history of which ones I had installed in the first place. Another fail on Mozilla's part in my opinion....

Enigma said

Stab in the dark, but do you by any chance have the 'Session Manager' installed  ? Some other user mentioned that this add-on turned out to be the culprit .....

No, i do not, at least not as far as I know or have seen. Not even sure what that is.... Thanks for the tip though!

You should see a "Legacy Extensions" section present on the about:addons page as the last tab that shows your extensions from Firefox 56 and older.

cor-el said

You should see a "Legacy Extensions" section present on the about:addons page as the last tab that shows your extensions from Firefox 56 and older.

You're talking about the "Unsuported" tab which is actually the last tab?? In the Add-ons Manager?? Legacy Extensions only appears once you have clicked on the "Unsupported" tab... Nope, not there. The only one that is there is the Adobe Acrobat - Create PDF add-on which has been disabled for I don't know how long. Otherwise, there is not a trace of anything that I had installed. I did not have a lot installed mind you, but it also mysteriously disappears after an update and I am sick and tired of having to go back and remember the names and track down the add-ons I had installed.

Thanks for the suggestion....

It is possible that a new profile folder got created and that only globally installed extensions show under unsupported. You might have an "Old Firefox Data" folder on the desktop if case the refresh feature in Firefox is used.

On the desktop? No, there is nothing there. I don't keep anything on my desktop, so when something appears there, it is completely obvious.

Could you check for any extra profile folders on disk? You can get to the Profiles folder from the Troubleshooting page. Either:

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Open in Finder" button. This should launch a new window listing various files and folders in Finder.

I'm a Windows person, so apologies for the lack of precision on the next step, but click up or left in the folder hierarchy to get to the Profiles folder. Other than the folder you were just viewing, are there any other profile folders here and, if so, were their contents updated recently?

jscher2000 said

Could you check for any extra profile folders on disk? You can get to the Profiles folder from the Troubleshooting page. Either:

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Open in Finder" button. This should launch a new window listing various files and folders in Finder. I'm a Windows person, so apologies for the lack of precision on the next step, but click up or left in the folder hierarchy to get to the Profiles folder. Other than the folder you were just viewing, are there any other profile folders here and, if so, were their contents updated recently?

Nope, just one folder under Profiles; a bunch of gibberish and then .default.

Do you use Time Machine or another backup program that might have saved some or all of that profile folder? It may cause issues to restore all of it, but you could use parts of it.

Most of the key files are described here: Recovering important data from an old profile.

Is there an extensions folder in the profile folder?

Try to rename/remove extensions.json.

jscher2000 said

Do you use Time Machine or another backup program that might have saved some or all of that profile folder? It may cause issues to restore all of it, but you could use parts of it. Most of the key files are described here: Recovering important data from an old profile.

Yes, I do use Time Machine, but that is waaaaaay to much work for this piddly little problem with FF... I know I am making it a big deal, because it's a royal PITA to have to do this every time, but not big enough to go hunting through TM..... Thanks tho....

I don't use Time Machine myself (I'm on Windows), but in one thread the user made it sound like when you're viewing the folder in Finder there is a way to grab an old file for that folder from Time Machine from a menu item in Finder. ??