Mattermost not working on iMac 2015

For a few weeks now, I can no longer open Mattermost on my iMac (Retina 5K, 27 inches, late 2015).
Model Identifier: iMac17,1. Installed System: macOS Monterey 12.7.2

The Mattermost window stays white even after reinstalling.
I even completely reinstalled the iMac, but Mattermost still doesn’t work.

Thank you for your help!

Take a look in %userprofile%\AppData\Roaming\Mattermost\logs and see what the logs say!

Thanks @john.oliver
Here is what appears in the log when I launch Mattermost :

[2024-01-04 10:16:40.106] [error] Logger Log level set to: info
[2024-01-04 10:16:40.302] [warn]  [App.Initialize] Current working directory is /Users/admin/Library/Containers/Mattermost.Desktop/Data, changing into /Applications/
[2024-01-04 10:16:40.391] [info]  [App.Utils] MAS: No files to migrate, skipping
[2024-01-04 10:16:40.417] [info]  [App.Initialize] Autoupgrade disabled: false
[2024-01-04 10:16:40.479] [info]  [ServerDropdownView] init
[2024-01-04 10:16:40.494] [info]  [i18nManager] Set new language fr
[2024-01-04 10:16:41.225] [info]  [ModalView] [welcomeScreen] preloading with /Applications/

Go the the three-dot “kebab” in the top-left corner and select Mattermost → Logs Look for “Logging level” and set to Debug. Then try again.

You can also try ⌘ ⇧ R to reset the cache… it’s possible that the reinstall didn’t actually remove the cache.

Thanks @john.oliver
But where can I find the kebab menu? (which app?)
And where do “try ⌘ ⇧ R” ?

In the Mattermost app

Unfortunately, it’s not working, and I don’t see the kebab menu (see my screenshot, everything is white or flickering…)

Try uninstalling, then delete %userprofile%\AppData\Roaming\Mattermost