2072491 - Firefox frequently fails to update on MacOS (Apple Silicon)

Status: NEW

(Toolkit :: Application Update, defect)

Description

[Wirawan Purwanto]

Attachment: Firefox-trying-install-new-helper.png

Steps to reproduce:

I am using the most up-to-date Firefox on a MacOS 26.5.1 (Tahoe) on a MacBook Pro M5 chip. I believe this was Firefox 155. This laptop is somehow (at least partially) managed by a company, so it is entangled by the meddling hands of enterprise settings etc. My experience of using Firefox on this machine is nothing short of annoying and terrible.

I have installed Firefox fresh from a direct PKG/DMG download from firefox.com). My user is basically also the system administrator on the machine and thankfully I have sudo access. First installation was always good, the Firefox usage was also ok (with some caveats which I am going to share in a different question/forum/bugzilla), until there was a prompt to update the Firefox. So, as a cood citizen, I agreed to the update process and followed through.

Actual results:

If I concur to update, Firefox will restart, and it gave me this popup window (which I will share as an attachment): it basically prompted me to enter my username and password, saying "Firefox is trying to install a new helper tool."

This is strange, IMO. First of all, why does it need a “new helper tool”?
But it has failed so many times in this way: When I entered my username and password in order to install the “helper”, nothing happened or showed up. The Firefox app quit afterwards.
After that, when I tried to run Firefox again from the launcher, it was just hung. And when I tried to start Firefox from CLI, it gave these errors repeatedly:

$ /Applications/Firefox.app/Contents/MacOS/firefox --safe-mode
^[2026-09-15 23:00:50.994 firefox[73106:21834118] Server doesn't exist or doesn't provide correct selectors.
2026-09-15 23:00:57.011 firefox[73106:21834118] Server doesn't exist or doesn't provide correct selectors.
2026-09-15 23:01:03.029 firefox[73106:21834118] Server doesn't exist or doesn't provide correct selectors.
(...more of the same error repeated…)
2026-09-15 23:01:39.118 firefox[73106:21834118] Server doesn't exist or doesn't provide correct selectors.
2026-09-15 23:01:45.128 firefox[73106:21834118] Server doesn't exist or doesn't provide correct selectors.
2026-09-15 23:01:46.129 firefox[73106:21834118] Unable to clean up updater.

The last line gives a clue that the updater couldn’t get cleaned up.

Anyone experiencing this issue? This has gotten so annoying. The only way to move forward if this happens is to reinstall Firefox. That is ridiculous, that I have to reinstall Firefox every time a new version comes out.

Expected results:

The new Firefox should launch as normal. This failure to update has happened more times than not on my device. The only one time I could recall that the update was successful (and I did not have to reinstall Firefox from scratch) was when I restarted my laptop. Either I upgraded right before or right after that; then the upgrade process succeeded.

Some additional info: the laptop has the following software installed by the company: Jamf, GoToResolveUnattended.

Comment 1

[Wirawan Purwanto]

Hi, I just found out after I wrote the bug report that there is a KB article about this: https://support.mozilla.org/en-US/kb/firefox-helper-tool-macos .

In my case, I did install Firefox through the official DMG image from firefox.com .

Comment 2

[BugBot [:suhaib / :marco]]

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

Comment 3

[BugBot [:suhaib / :marco]]

The severity field is not set for this bug.
:Amir, could you have a look please?

For more information, please visit BugBot documentation.

Comment 4

[Stephen A Pohl [:spohl]]

Firefox only asks to install its helper tool when it determines that it can't install an update on its own, usually because the current user doesn't have permission to change some of the files inside Firefox.app. Since you're an administrator and installed Firefox yourself, that shouldn't be the case here, so we'd like to find out what changed the permissions on Firefox.app. Let's try this as follows:

1. Restart your Mac.
2. Before opening Firefox, open Terminal, run the following and paste the output here:

whoami
dseditgroup -o checkmember -m "$(whoami)" admin
ls -ldO@ /Applications/Firefox.app
find /Applications/Firefox.app ! -user "$(whoami)" | head -20
find /Applications/Firefox.app -exec test ! -w {} \; -print | head -20
ls -l /Library/PrivilegedHelperTools/org.mozilla.updater /Library/LaunchDaemons/org.mozilla.updater.plist

3. Open Firefox, go to "Firefox" > "About Firefox" and install the update if one is offered. Let us know whether you get the helper tool prompt again and whether the update succeeds.
4. Afterwards, attach last-update.log and backup-update.log from ~/Library/Caches/Mozilla/updates/Applications/Firefox/updates/ to this bug, if they exist.

Could you also let us know:

• Did you install Firefox from the .pkg file, or by dragging it from the .dmg into Applications?
• Does your company install or update apps on this Mac through Jamf, and has it ever installed or updated Firefox?