This question already has answers here: After most recent kernel update (4.15.0-44-generic) my tablet freezes whenever plugged into docking station (3 answers) Closed last year .

I have been using Ubuntu 18.04.1 LTS on a Dell Precision 5510 laptop with a Dell Thunderbolt 3 Dock, model TB16, for over two months with no issues. The system is regularly updated with the latest updates.

January 29th 2019, a notification for a new update appeared :

Several unused kernel files to be deleted

(update for Oracle's Virtual Box, seems very irrelevant)

I proceeded to install. However after rebooting, reaching the login screen and entering my password, I only had black screens and a completely unresponsive system.

After several reboots and attempts to diagnose the problem, only when I rebooted the system with the Dell Thunderbolt 3 Dock unplugged that the system successfully booted and displayed the desktop, menu bar...etc. Even then, when I re-plugged the dock, the system became unresponsive with a black screen.

I am currently looking into restoring the pre-update kernel using GRUB.

I'm interested to know if anyone, with a relatively similar setup, is experiencing this issue. Any other insights or ideas that could help are welcome.

Update :

Another report on this issue found (2 posts by the same author), it seems to affect only Dell docks but it is probably not restricted to Dell machines:

https://answers.launchpad.net/ubuntu/+question/678174

After most recent kernel update (4.15.0-44-generic) my tablet freezes whenever plugged into docking station

For now the issue has been resolved by restoring 4.15.0-43-generic using GRUB. I am holding from updating Ubuntu until the bug gets fixed.