While trying to pass my 1050TI graphics card into an Ubuntu 20.04 VM on a new Proxmox server, I kept running into the following error...
I searched forums and blog posts for days, playing with almost every step of the Proxmox GPU pass through guide until I finally found this post.
The fix was simple. The original guides included this line to be added to the grub config at /etc/default/grub
The fix was to change the last few configuration flags for the video from video=vesafb,efifb:eek:ff to video=vesafb:off video=efifb:off. For whatever reason, grub doesn't like those values provided in csv format.