(EE) Failed to load module "fbdev" (module does not exist, 0)

This is a wiki page. Be bold and improve it!

If you have any questions about the content on this page, don't hesitate to open a new ticket and we'll do our best to assist you.

Sample excerpt from Xorg logs:

gentoo-victoria log # cat Xorg.0.log | grep EE
   (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
   // ...
   [18.985] (EE) Failed to load module "fbdev" (module does not exist, 0)

Reason: there should be a fbdev driver in the following location but it is missing:

/usr/lib/xorg/modules/drivers/fbdev_drv.so

The official X.org documentation:
https://www.x.org/wiki/fbdev/
Driver for Linux framebuffer devices.

Solution: on Gentoo systems, install the package x11-drivers/xf86-video-fbdev.

Remaining questions to be answered and documented here:
What is a framebuffer. In which conditions would I need a fbdev driver?
Is the fbdev driver used as a fallback for my currently unsupported nvidia graphic card?

https://en.wikipedia.org/wiki/Linux_framebuffer