2026214 - Live policy not applied to client when reverting it

Status: VERIFIED FIXED

(Enterprise Products :: Firefox, defect)

Description

[lburuian]

Found in

• Firefox Enterprise 149.0b11
• Console: stage version from Mar 24, 2026, 4:25 PM

Affected environment

• Staging

Tested platforms

• All platforms

Preconditions

• Have SSO credentials for console enabled.
• The user is logged into Firefox Enterprise client.

Steps to reproduce

1. Log into the console and set the BlockAboutConfig as TRUE
2. Wait for a few minutes and verify that the policy is correctly set in the client, in about:policies
3. In the client, visit about:config. => The page is blocked
4. In the console, set the BlockAboutConfig as False
5. Wait for a few minutes and verify that the policy is correctly set in the client, in about:policies
6. In the client, visit about:config.

Expected result

• The policy is updated in about:policies and the page is no longer blocked in the client.

Actual result

• The policy is updated in about:policies but the page is still blocked in the client.
• The page is unblocked after a restart.

Additional notes

• This is marked as a live policy and should work without a restart.
• More info: https://searchfox.org/enterprise-main/rev/d0d4965597a62345f11a76862b6f17c3deab4af6/toolkit/components/enterprisepolicies/tests/browser/browser_policies_missing_live.js#15

Comment 1

[lburuian]

Attachment: Screencast from 2026-03-25 17-12-57.webm

Comment 2

[Miruna Curtean]

Same applies to DisableDeveloperTools - dev tools are normally enabled.

1. When the policy is configured it is set to true and this applies in the client about:policies and in hamburger menu> tools, without browser restart and dev tools are not accessible.
2. When the policy is disabled, access to developer tools is not restored without restart.

Comment 3

[:gerard-majax]

This is covered by tests, so it is surprising to break. Can you share browser console logs (not devtools)? Make sure to enable multi-process.

Comment 4

[lburuian]

Attachment: console-export-2026-3-27_15-46-55.log

Hello,
We have reproduced this again, made another video and saved the Multiprocess Browser Console logs. The test was performed on Ubuntu 24.
Please let us know we can help with anything else.
Thank you.

Comment 5

[lburuian]

Attachment: Screencast from 2026-03-27 15-45-23.webm

Comment 6

[Miruna Curtean]

Attachment: macOS Disabledevtools console-export-2026-3-27_15-50-6.log

Here is also a recording of the process and the console log for DisableDeveloperTools, using the steps as specified in https://bugzilla.mozilla.org/show_bug.cgi?id=2026214#c2 using macOS Tahoe 26.3 and the Firefox Enterprise 149.0b11 (Build ID:20260325025433) build.

Comment 7

[:gerard-majax]

Ok, thanks, can you try just removing the policy instead?

Comment 8

[BMO Github Automation]

Attachment: [mozilla/enterprise-firefox] Bug 2026214 - Fix live policies (#622)

Comment 9

[:gerard-majax]

Ok I'll cover only those two in this bug and we will go over policies in https://bugzilla.mozilla.org/show_bug.cgi?id=2027104

Comment 10

[lburuian]

Attachment: Screencast from 2026-03-30 10-53-48.webm

Hello,
I tested this again this morning and it seems that removing the policy (setting it to Firefox Default) is applied live, as oposed to setting it to False and leaving the policy active in the client (you can see it in about:policies).
Please see attached video.
Please let us know if we can be of further assistance.
Thank you.

Comment 11

[:gerard-majax]

Thanks, it confirms my diagnosis and my PR makes sense

Comment 12

[BMO Github Automation]

Authored by Alexandre Lissy
https://github.com/mozilla/enterprise-firefox/commit/d6dd18c564e45fb6e8535e87a1e0c7f88d5992c4
[enterprise-main] Bug 2026214 - Enterprise: improve about:config blockage test

Authored by Alexandre Lissy
https://github.com/mozilla/enterprise-firefox/commit/ab2cb93fdbb5cd8a37d9bf22764cff6da4e26481
[enterprise-main] Bug 2026214 - Enterprise: properly apply BlockAboutConfig and DisableDeveloperTools

Authored by https://github.com/lissyx
https://github.com/mozilla/enterprise-firefox/commit/c01d8e45eccad44c04ddb853b4eefd1410d6e3eb
[enterprise-main] Merge pull request #622 from lissyx/enterprise-bug2026214_live_policies

Comment 13

[lburuian]

An interesting thing we noticed today, after further testing: It seems that, once you set to policy to False and it does not get applied live, setting it to Firefox Default no longer works either.
It is like setting the policy to False breaks things and nothing works anymore until a restart is performed.
It might be the same root cause and the fix might work for this scenario as well, but we thought it is worth mentioning.
Thank you.

Comment 14

[lburuian]

I tested this again on Windows 11, using FxE 151.0a1 (2026-04-09), build ID: 20260409215615 for BlockAboutConfig. The policy is successfully applied live, without the need for restart.
Verified for both True > False and True > Fx Default. The page gets blocked and unblocked as expected.
See video here.
We will check on other platforms asap.
For DisableDeveloperTools we have an open bug and are tracking changes there (2028825).
Thank you.

Comment 15

[Miruna Curtean]

Verified fixed on macOS Tahoe 26.3 using enterprise-release build 149.2.0 (20260410164811). The True > False and True > Fx Default>True flow gets applied in about:policies and about:config without restart.

Comment 16

[lburuian]

The fix works as expected on Ubuntu 24 as well, with FxE 151.0a1 (2026-04-09), build ID: 20260409215615.
Marking this as Verified.
Thank you.