Enabling then disabling experimental OpenGL breaks GUI

Question

After enabling, then disabling, the experimental OpenGL driver, I cannot use the GUI anymore.

1. Autologin to GUI no longer works
2. Manual startx and xinit no longer work
3. I am getting the error: Fatal server error: (EE) no screens found(EE)

How can I fix this?

Answer 1

Installing (or reinstalling) the xserver-xorg-video-fbturbo package fixes this issue:

sudo apt install xserver-xorg-video-fbturbo

or

sudo apt install --reinstall xserver-xorg-video-fbturbo