2026219 - The Weather widget, Shortcuts and Recommended stories sections cannot be disabled from the Customization panel after a browser restart while the new tab is focused

Status: RESOLVED FIXED

(Firefox :: New Tab Page, defect)

Description

[Valentin Bandac [:vbandac], Ecosystem QA]

[Affected versions]:

• Firefox Release 149.0 (Build ID: 20260318190823)

[Affected Platforms]:

• Windows 11 x64
• Linux Mint 22.4
• macOS 15.6.1

[Prerequisites]:

• Have a Firefox en-US locale installed.
• Have the browser region set to US.
• Have the "151.0.20260325.53807" newtab add-on version downloaded from here.

[Steps to reproduce]:

1. Open the browser with the profile from prerequisites.
2. Navigate to the "about:addons" page and click the gear wheel button from the top-right part of the page.
3. Select the "Install Add-on From File..." option and install the add-on from the prerequisites.
4. Restart the browser and open a new tab page.
5. With the tab still in focus, restart the browser.
6. From the Customization panel, toggle off the Weather widget, Shortcuts and Recommended stories sections.
7. Observe the new tab page.

[Expected result]:

• The Weather widget, Shortcuts and Recommended stories sections are not displayed anymore on the new tab page.

[Actual result]:

• The Weather widget, Shortcuts and Recommended stories sections are STILL displayed anymore on the new tab page.

[Notes]:

• This occurs after each restart.
• This occurs only on the focused tab, after restarting the browser.
• If the tab is refreshed, the toggles on the Customize panel work as expected - the content can be enabled/disabled accordingly.
• This issue is also reproducible if the add-on was installed through the Nimbus rollout.
• Attached a recording of the issue here.
• This issue is NOT reproducible without the addon from the prerequisites installed.

Comment 1

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 2026219 - Set browser.newtabpage.activity-stream.selfLoading.enabled asap when instantiating ActivityStream. r?#home-newtab-reviewers!

This greatly increases the odds that the preference is set properly for train-hops
before the first about:home document loads, which increases the odds of loading the
React 19 version of the document.

Comment 2

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 2026219 - Set browser.newtabpage.activity-stream.selfLoading.enabled asap when instantiating ActivityStream. r?#home-newtab-reviewers!

This greatly increases the odds that the preference is set properly for train-hops
before the first about:home document loads, which increases the odds of loading the
React 19 version of the document.

Comment 3

[Mike Conley (:mconley) (:⚙️)]

Per discussion, we're going to attempt to do this by temporarily maintaining compatibility of the toggles for both React 16 and React 19.

Comment 4

[Nathan Barrett [:nbarrett]]

Attachment: Bug 2026219 - Add fallback events for moz-toggle for react 16 compat r=maxx

Comment 5

[Nathan Barrett [:nbarrett]]

Attachment: Bug 2026219 - Add fallback events for moz-toggle for react 16 compat r=maxx

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/538fa3968ae1
https://hg.mozilla.org/integration/autoland/rev/192bcc3c12ba
Add fallback events for moz-toggle for react 16 compat r=maxx,home-newtab-reviewers

Comment 7

[amarc]

https://hg.mozilla.org/mozilla-central/rev/192bcc3c12ba

Comment 8

[BugBot [:suhaib / :marco/ :calixte]]

Since nightly and release are affected, beta will likely be affected too.
For more information, please visit BugBot documentation.

Comment 9

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:nbarrett, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
  • See https://wiki.mozilla.org/Release_Management/Requesting_an_Uplift for documentation on how to request an uplift.
• If no, please set status-firefox150 to wontfix.

For more information, please visit BugBot documentation.