When I launch a steam game called "The Binding of Isaac", and its running and open the Icon on the sidebar/dash/favorites (I'm not sure what its called) is blank i tried verifying the install from steam i tried restarting but it doesn't fix it. I saw another post on here about this Unity launcher and Steam icons
I also tried that it doesn't help
If no icon is found, a generic icon should be shown. That now you see a "black" icon leads me to suspect that there could be an issue with the icon referred to in the .desktop launcher you are showing in the linked image.
Thus, locate the icon file and check it. It should have an extension .png or .ico or .svg.
To create your own icon, create a hidden folder .icons or .local/share/icons in your home folder, and put a valid .png or .svg icon graphic in the folder. Then that one will be used.
