Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Addons stop working when using Firefox on two clients at the same time in a domain joined network

  • 2 replies
  • 1 has this problem
  • Last reply by MrCheeze

more options


I've had a strange issue with Firefox on my work PC for a a few years now. That I'd like to solve once and for all. I have a workaround that has gotten me back to work reasonably fast, but I recently added another addon that makes this process take a lot longer than it did before... Since I have to recreate the data that I previously added to this addon manually. The work around is to "Refresh Firefox" from the "about:support" page.

At work everyone has their own (windows 10) computer, each computer is domain joined and sync all user folders. (including AppData) Usually we only use our own computer, but from time to time we have to log in to another computer. (Like a laptop to do some work away from the desktop) However when I do that and accidentally open Firefox on both my main computer and the second computer at the same time, all my addons stop to work "partly" on my main computer... (I don't use addons on the laptop/other computers so I don't know if they stop to work on those ones too or not)

When I say partly, I mean that they load and show up on the toolbar, I can open the "Drop down meny" on some of the addons, but not all. Some load the menu correctly and some only show a white box. But when they show up they seem to have lost "my settings" or the data that they should show. And I can't save any new data.

I can't change settings for the addons in the addon page. Only deactivate/activate them but that doesn't get them back either. But the same thing goes here, some show the settings page correctly, some don't. But all of them have forgotten "my settings" and I can't save any new settings/data. (Note that this isn't necessarily happening for the same addons that couldn't show the drop down menu. Eg. addon 1 might show the drop down but not the settings page. While addon 2 might show the settings page but not the drop down and the 3:rd might show both. etc.)

And the functionality that they bring might work partly or not at all.

This is happening for all of my addons and not just one of them.


I've tried to enable logging globally for all addons following the instructions on this forum: I've attached the loggs as "troubleshooting information"

Now I'm getting a lot of errors looking like this: IndexedDB UnknownErr: ActorsParent.cpp:562

I'll ad a link to the Firefox source that this error references. I don't think this is the version that I'm using since the row that generates the error is just a comment. But if it looks anything like this file it seems to be something with a hash that gets created for this file? That possibly gets corrupted when it gets updated by two clients concurrently? I'm not sure as i didn't dig so deep in the source...

I googled a lite about IndexedDB and from what I understood it is some database that Addons create and use to store their data? If that is the case, can it bee that this file somehow gets corrupted when it gets written to by two clients at the same time? Or might it be that one of the clients overwrites the changes that gets written by the first client?

Is this a bug? Or is it something that I need to reconfigure somewhere?


Firefox version: 81.0.1 - 64 bit (The latest one that i can get at the moment) Addon List:

  • Dashlane (Password manager)
  • Facebook Container (From Firefox)
  • Tab-Counter (Shows a count of the amount of tabs and windows open at the moment) (Currently have 50 windows open and a total of 1874 tabs open...)
  • uBlock Origin (Ad blocker)
  • Web Scrobbler (For
  • Window Titler (For naming all the windows so its easier to find the window or tab that I need. This is the addon that I have to manually add the data to again after refreshing Firefox... See my problem? ;) )

If you want me to test anything or supply you with some other logs just tell me!

Thanks in advance! (And sorry for the wall of text)

All Replies (2)

more options

You can create a new profile as a quick test to see if your current profile is causing the problem.

See "Creating a profile":

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

more options

Hi Cor-el! Thanks for your answer!

Isn't that whats happening when I "Refresh Firefox"? Only thing is that i can't go back to the old profile anymore since Firefox removes the old profile and puts it on the desktop if there would be anything that I need to restore manually?

I did go through the code of the "Window Titler" addon and found that it stores the names of the windows in the "sessionstore.jsonlz4" file and refreshing Firefox and copying that file in to the new profile works when it comes to restoring the data that got missing! So now I have a workaround again that gets me back to business pretty fast! But it would be nice to get a solution for the main problem! (So I don't have to use the workaround ;) )

I know Firefox has a MSI installer for business. However I used the regular EXE installer when I installed it since I'm the only one that uses it here... (I know its sad :/ ) But I do have a hard time seeing that the installations would be any different from each other, but could it have some extra code that handles situations like this? Or is it something that needs to be added to Firefox?