[Bug]: Windows Tray icon disappear

[baek-sang]

Checks before filing an issue

• This issue doesn't reproduce on web browsers (such as in Chrome). If it does, issue reports go to the Mattermost Server repository.
• I have checked the issue tracker and have not found an issue that matches the one I'm filing. This should include closed issues.
• This issue is not a troubleshooting question. Troubleshooting questions go here: https://forum.mattermost.com/c/trouble-shoot/16.
• This issue is not a feature request. You can request features and make product suggestions here: https://mattermost.com/suggestions/.
• This issue reproduces on the most recent stable version, or the most recent prerelease version of the Mattermost Desktop App.
• I have read the contribution guidelines.

Mattermost Desktop Version

6.0.4

Operating System

Windows 11 25H2

Mattermost Server Version

11.3.0

Steps to reproduce

1. Lock Windows
2. Monitor off
3. Relogin windows

Expected behavior

Show tray icon

Observed behavior

Log Output

[2026-02-03 02:48:50.400] [error] [WebContentsEventM...] [renderer] Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'sidebarBg')
[2026-02-03 02:49:09.627] [error] Logger Log level set to: { level: 'info' }
[2026-02-03 02:49:09.707] [error] Logger Log level set to: { level: 'error' }
[2026-02-03 02:49:09.920] [error] [App.Utils] updateServerInfos: Failed to fetch remote info {
  error: 'Error: net::ERR_SSL_CLIENT_AUTH_CERT_NEEDED\n' +
    '    at SimpleURLLoaderWrapper.<anonymous> (node:electron/js2c/browser_init:2:124653)\n' +
    '    at SimpleURLLoaderWrapper.emit (node:events:519:28)'
}

Additional Information

Windows - Dark mode
Mattermost Icon Color - Light

[devinbinnie]

I can't seem to reproduce this. Does a reinstall of the application fix it? Does this happen every time you lock the screen?

[baek-sang]

@devinbinnie

The issue persists even after a clean install. It appears to be a long-standing bug. In my case, locking Windows does not consistently reproduce the bug.

[robby-ac]

Do you have the icon pinned to the taskbar?

If yes, right click it and unpin, then uninstall the app, run disk cleanup (system files), reboot the PC, reinstall mattermost, pin to taskbar again

I think this is a long standing windows bug rather than mattermost specific, but it is regularly triggered by whichever method which mattermost updates, I have several other apps that do this as well

Maybe the windows store change coming up will prevent this happening

[baek-sang]

@robby-ac

Reinstallation and rebooting are not necessary. just need to quit and restart the app.

Also, reinstalling doesn't completely fix the issue. I have 12 tray icons, but this problem only occurs with Mattermost.