Today attempted to upgrade from 20.04 LTS to 22.04 LTS. Encountered some problems during upgrade, but those appeared to have resolved themselves (see below). Once I hit the "Restart Computer" button, however, the GUI disappeared and was replaced with a full, blank screen with an error message starting:
/shutdown: error while loading shared libraries: libsystemd-shared-249.so: camo
open shared object file: No such file or directory
[144120.321497] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00007f00
The screen is unresponsive to mouse or keyboard input. I attempted to power-down the machine and restart but the power key is not responding. (This is a Lenovo Thinkpad where Ubuntu 20.04 LTS was factory-installed.)
I am currently unable to turn the computer off.
(During the installation, a prompt came up indicating that Firefox was to be installed via 'snap'. I hit the "Next" button to allow the upgrade to proceed, but encountered problems similar to that described in 22.04 Installation Hung at Firefox snap. I hit Ctrl-C a couple of times, but eventually the upgrade process resumed and continued to the point of "Restart Computer.")
Suggestions as to how to proceed? Thanks.
