Firefox request password to install helper tool but will not launch

[Jboss117]

I have a user at my job that installed the latest Firefox update (13324.11.21) through our MDM. After installing this update she cannot launch Firefox. When attempting to launch she receives a request for a username and password to install a Helper Tool. She is an admin on her machine and enters her credentials. The message closes and nothing happens. When attempting to launch again the same thing happens. This is not happening with our other 100 Macs who have the same Firefox version and others who have the same OS.

Is anyone able to tell me why this is happening or how to fix? Any assistance is very much appreciated.

The below troubleshooting steps have been done:

Uninstalled and reinstalled Firefox

Updated the OS to 15.0.1

Disabled the Master Password on Firefox through a Mac Profile

Checked if there was a Firefox file under /Library/PrivlegedHelperTools

Granted Full Disk Access to Firefox under System Settings

[mkaply]

Could you open up a bugzilla bug for this?

https://bugzilla.mozilla.org/enter_bug.cgi?product=Toolkit&component=Application%20Update

The team that works on updates hangs out there.

[mkaply]

This problem sounds similar to this:

https://bugzilla.mozilla.org/show_bug.cgi?id=1957613

[christophholzapfel]

Solution (here macOS 26.4.1 and Firefox 150.0):

Delete the complete folder updates in ~/Library/Caches/Mozilla

[bsmth]

Thanks a lot for raising and for the comments, we're tracking this over in the linked bug (1957613), so going to close for now, thanks

[tvdeyen]

Solution (here macOS 26.4.1 and Firefox 150.0):

Delete the complete folder updates in ~/Library/Caches/Mozilla

Updated FF to 151 after deleting the caches and now my Selenium tests are working again.