18.04 - the screen froze and kicked me out, upon login Im kicked back out
 

Installed a fresh install 18.

Spent a day installing a few apps and just getting used to the new front end. Last night I clicked on Show Applications and the applications screen opened then froze after showing only three applications. I let it sit about five minutes. I then did a hard restart. I put in my user and pass and the screen lags for about 30 seconds after hitting enter. Then the desktop starts to show up, you can see the trash icon on the screen and then you are kicked out back to the login screen.

I was lucky enough to have a second account setup so I login and looked in the logs. There is a lot of stuff but nothing that is clear (to me).

This morning I turned on my machine, tried to log into the troubled account and then
immediately into the other account and find this in the log:

spice-vdagent,
Cannot access vdagent virtio channel /dev/virtio-ports/com.redhat.spice.0
priority 3

gnome-session-b
CRITICAL: We failed, but the fail whale is dead. Sorry.... [2]
priority 2

gnome-session-b
Unrecoverable failure in required component org.gnome.Shell.desktop
priority 3

which log?

that's gnome in a nutshell:
its devs are apparently so over-confident that they don't even bother providing proper error messages.

you might still find something in

Opened log and clicked on Important.

This is from dmesg:
[ 50.343377] PKCS#7 signature not signed with a trusted key
[ 50.343387] kpatch_livepatch_Ubuntu_4_15_0_23_25_generic_40: loading out-of-tree module taints kernel.
[ 50.343389] kpatch_livepatch_Ubuntu_4_15_0_23_25_generic_40: tainting kernel with TAINT_LIVEPATCH
[ 50.343458] kpatch_livepatch_Ubuntu_4_15_0_23_25_generic_40: module verification failed: signature and/or required key missing - tainting kernel
[ 50.391392] livepatch: enabling patch 'kpatch_livepatch_Ubuntu_4_15_0_23_25_generic_40'

Messages in both dmesg and journalctl are in the important log entry.
The above is from today - probably because I rebooted and it couldnt connect online.