Unable to load mattermost after upgrade

Troubleshooting
1

Summary
After upgrading Mattermost, I am unable to load any of its UI, other than the initial “App or Browser?” preference page. After I click “Browser”, I only get a blank page.

Steps to reproduce
Mattermost Version: 9.10.0
Database Schema Version: 121
Build Number: 9713988960
Database: postgres

I am using Firefox v128.

All I did was reload mattermost after it was upgraded by our sysadmin.

I have cleared all settings and cookies for this site, as well as attempted to load in private mode, as well as disabled all extensions. Enhanced tracking protection is OFF.

The site DOES work in Chrome (Chromium Version 126.0.6478.182 (Official Build) snap (64-bit)).

Expected behavior
It used to function perfectly well. Other people in the same org using the same server and the same browser and OS report no issues. I cant figure out whats wrong here.

Observed behavior
After upgrading, every page load is blank.

The JS console shows this error:

Uncaught (in promise) ReferenceError: Notification is not defined
Me index.tsx:17
React 7
unstable_runWithPriority scheduler.production.min.js:18
React 6
id root.tsx:283
promise callback*66433/id/< root.tsx:279
id root.tsx:403
componentDidMount root.tsx:412
React 2
unstable_runWithPriority scheduler.production.min.js:18
React 4
unstable_runWithPriority scheduler.production.min.js:18
React 2
F scheduler.production.min.js:16
onmessage scheduler.production.min.js:12
73323 scheduler.production.min.js:12
Webpack 16

2

Hi satellitecam, I’m sorry to hear you’re experiencing this issue, and thank you for providing detailed information. For starters, have you tried clearing your Firefox cache or using a different profile to see if the issue persists?

3

Yes, none of that helped.

However, the sysadmin updated again today to 9.10.1, and that has fixed the error, and the client now loads again.