Found in

• 107.0b9 MSIX

Affected versions

• 107.0b9MSIX

Tested platforms

• Affected platforms: Windows 10x64
• Unaffected platforms: macOS, Ubuntu

Preconditions

• have Firefox 107.0b9 MSIX installed

Steps to reproduce
Unfortunately, I don’t have steps for this issue. This occurred to me today after trying to start Firefox 107.0b9 MSIX after waking up the PC from sleep. We tried multiple times to reproduce the issue by restarting the PC and going to sleep but without any luck.

What I’ve done is:

1. Started PC from sleep
2. After some time (like 1h) I clicked to open Firefox 107.9b MSIX from the store
3. On the profile manager I left the selected profile (I assume that this is the one I used last time) and clicked to Start Firefox
4. Waited some time and nothing happened. Inside Task Manger Firefox was displayed with 10% CPU.
5. I closed the process and tried to start Firefox MSIX again with a new profile.
   The same thing happened with a new profile, Firefox process was shown inside Task manager but the browser was not displayed.
6. After ~1 minute the browser is displayed with disabled language addons.

Expected result

• Firefox should have started almos instantly with enabled language addons.

Actual result

• Firefox started very late with disabled language addons.

Regression range

• I don’t think we could find a regression range here.

Additional notes

• Attached the browser console logs after opening Firefox MSIX.
• Unfortunately I only had 107.0b9 MSIX installed at that point so I don’t know if this happens on other Firefox versions as well.
• I could successfully enable the addons after starting Firefox.

Something similar occurred on my Windows 11 as well. I have Windows 10 and Windows 11 in multiboot. I switched to win11 and started Firefox MSIX 107.0b9 and 106.0.5 from MS Store. On both Firefox builds the skeleton UI was displayed and Firefox was not loaded. Firefox was started after some time after force closing it and reopening it again. I tried to restart the PC multiple times and I can no longer reproduce the issue. Please see the attached screen recording.
Note that I don't have profile manager enabled on Windows 11 so maybe that is the reason why the skeleton UI was displayed as opposed to Windows 10 where I have the Profile manager enabled and Firefox browser was not displayed after clicking Start Firefox inside the profile manager.

I think we cannot find out a regression range for this bug given its nature, and it will also be time consuming for QA. I'm going to remove the regressionwindow-wanted keyword in this case.

I don't know what to make of this -- the Disabling foreign installed add-on langpack-de@firefox.mozilla.org in app-profile messages suggest some interaction with old profiles. If we can't repro, I don't think we should spend too much time running it down.