Ubuntu 18.04 (Bionic Beaver) hangs on purple login screen

Question

Every time I run a software update and shut down my computer, it breaks on the next boot.

This time, it hangs on the login screen. I can't move my mouse, nor type on the keyboard.

I have a Dell XPS 13 7390 laptop.

Bios Version: 1.3.1
Ubuntu 18.04 Bionic Beaver

I thought it might be a video driver problem and have tried adding nomodeset to grub kernel to no avail.

Errors in journalctl -b:

MODSIGN: Couldn't get UEFI MokListRT
PKCS#7 signature not signed with a trusted key
Unable to register Frequencey manager -22
pam_systemd(su:session): Failed to connect to system bus: No such file or directory

I am not convinced any of these are connected to my problem.

Other things to note: I am unable to connect to the internet in recovery mode, even with eth connected I can't ping anything. Trying to enable networking in recovery mode also hangs with no human-readable errors.

Before I resorted to a factory reset, but this time I am trying to avoid that at all costs.

Any guidance would be appreciated.

Answer 1

Have you tried ALT+F2 or ALT+F3 to get another login screen? I think ALT + F10 takes you to system log where you can see what happened.

Answer 2

Had the same issue.

For me it was a problem with the kernel Linux 4.15.0-1066-oem

Restart and hit Esc to enter GRUB bootloader - select advanced options and boot from Linux 4.15.0-1065-oem (assuming you have that).

You can then remove 1066 from your packages and await Dell fixing it in 1067...