I did a system update on my elementary OS 6 Odin system with Nvidia GeForce GTX 1660 Ti. After a reboot I'm left with a black screen, unable to log in. Using Ctrl+Alt+F2 gets me into TTY2, but I am unable to launch
lightdm and log in.
This is a regression in Ubuntu 20.04. Anybody who has
nvidia-driver-470 and updates to kernel version
5.11.0-34-generic will experience black screen. A temporary walkaround is to log in to a TTY (Ctrl+Alt+F2) and remove all nvidia-related packages:
sudo apt purge nvidia-driver-470 nvidia-kernel-common-470 ...
You can just type
sudo apt purge nvidia and hit ↹ Tab to see all the nvidia packages that are still installed.
After doing this, I could get into Pantheon just fine.
If you've also experienced this, please check “This affects me” in the Ubuntu bug tracker!