Steps to reproduce:

Pre-requisites:

• Have a Firefox version that is not the latest (an update must be available)
• Have multiple profiles (in this example I'll call them P1 and P2)
• Enable Firefox to open multiple profiles at once

Steps to Reproduce:

1. Open one of the Firefox Profiles (for example P1)
2. Download the available Update
3. Launch the other profile (P2)
4. Wait for the second profile to install the downloaded update
5. On the first profile (P1) try to load any new website

Actual results:

In the first profile, no pages load. All pages will show loading forever but never load anything

Expected results:

When opening the second profile in step 3 (P2), Firefox should not install the update if another profile is open. It should wait until no other profile is open before installing. Preferably a warning should be issued stating an update is ready but will only be installed when other Windows are closed and give the option to "Proceed and update later" or "Close other windows and install update"

The Bugbug bot thinks this bug should belong to the 'Toolkit::Startup and Profile System' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Thanks for filing a bug!

We are aware of this problem. We are working on doing something about it, but the solution is a bit complex. You can read Bug 1480452 for details.

(In reply to Jair from comment #0)

Firefox should not install the update if another profile is open. It should wait until no other profile is open before installing.

We have considered this, but we are pretty reluctant to do it. There is a lot of malware out there that tries to prevent browsers from updating. We don't really want to make it possible to prevent us from ever updating just by pretending to be an already-running instance of Firefox.

Preferably a warning should be issued stating an update is ready but will only be installed when other Windows are closed and give the option to "Proceed and update later" or "Close other windows and install update"

Hmm, it might be reasonable to do something like this. I was originally going to mark this as a duplicate of Bug 1480452 but, since it will probably take us a long time to fix that, I'm instead going to keep this bug open as a place to discuss making a change like this in the meantime. It could probably be done much more quickly than fixing Bug 1480452.

There are a number of issues however, that we will have to figure out how we would want to address:

It could be fairly difficult to have a "Close other windows and install update" button. We would probably have to create a way of messaging the other browser(s), asking them to close, and then tracking when and if they actually do. It's a bit unclear what we should do if they don't actually close. One potential way to resolve this would be to instead have an "Update anyways" button, and leave closing the other windows to the user.

While this option is better than just preventing updates because it gives the user the option to install the update, it's always a bit of a security concern to assume that users are going to know better than to do something potentially harmful (ex: seeing this window when no other copy of Firefox is running and always clicking "update later"). A potential option to address this sort of situation would be make it more of an information box rather than a choice.