Eventually, every Linux user opens an app and finds a generic placeholder icon staring back from their dock/panel. It looks like the dock is broken, but it almost never is - the cause is a single line in the app’s .desktop file, and it only takes a minute to fix. Here’s how to find it and fix it yourself, on any desktop.

As the maintainer of Plank Reloaded, the most common bug report I get is “this app has the wrong icon.” It’s almost never the dock - it’s a broken StartupWMClass in the app’s .desktop file. So I wrote up how to find the right value on X11, Wayland, and KDE, and why deleting the line often fixes it.

  • zquestz@lemmy.worldOP
    7·
    15 hours ago

    Yeah something isn’t being matched right. Might want to look at both .desktop files and compare them. Probably be pretty obvious when you look. =)

    • angel@sopuli.xyz
      5·
      13 hours ago

      I just checked the .desktop file for firefox nightly. It contains only firefox-nightly as its StartupWMClass. So I went ahead and also checked the window class firefox nightly is running as and found the following: Screenshot showing the window properties of firefox nightly in the KDE system settings

      Does this mean that firefox nightly is using both, the firefox and the firefox-nightly window classes?