I recently performed a fresh install of Ubuntu 20.04. After installing Minecraft and Steam, I attempt to open them both. Both refuse to open because "GLX extension missing." I used 18.04 and 19.10 on this device, both Steam and Minecraft worked perfectly. Yesterday, I upgraded to 20.04 and played Minecraft with a friend, and I played a bit again this morning. But I was having other issues with 20.04, so I decided to give it a fresh install. Now I'm getting these errors.
Like I said, I had no problem running Minecraft or any Steam games until after the fresh installation. Nothing is claiming to have unmet dependencies.
EDIT: I just rebooted after doing nothing to the system except installing Java 8. I'm locked to 960x540 for some strange reason. That's the resolution everywhere except for the splash screens when shutting down and starting up