I posted here a question regarding battery issue with Thinkpad: Thinkpad P51 battery life 2.5 hours
I have followed the tutorial https://www.linuxbabe.com/desktop-linux/switch-intel-nvidia-graphics-card-ubuntu for switch to nvidia since was suggested.
After enabling nvidia it asked for set a password for enable UEFI secure boot. I set a password and after reboot I click "MOK enroll" and before I finish to enter password the system load ubuntu.
Now when I try to login on ubuntu, it said "Failed to start session".
I think that because I didn't add full password when it asked MOK enroll...
How to fix this as I can't now even login on Thinkpad (for this reason I am posting with this account).
Any help is much appreciated as now I stuck :(