11.3 - Boot stuck after "loaded plugin middlewared.plugins.crypto"

Boots get stuck after:

middlewared: loaded plugin middlewared.plugins.crypto'

My first instinct was to open '/var/log/middlewared.log' (attached).

It seems like the error is: ModuleNotFoundError: No module named 'freenasUI.storage'.

The system is a fresh-ish install of 11.3.
/etc/version says: "FreeNAS-11.3-U1 (34d6357440)"

My system is an HP Microserver Gen10 x3418.

The only non-standard procedure I had to do was to fix a Microserver specific boot problem using this: https://www.ixsystems.com/community/threads/11-2-hpe-microserver-gen-10-installation.71726/ 

Afterwards, the system was running and rebooting without a problem. I then used the GUI to do some normal settings, added a storage pool, created an smb share, added a user, deleted a user and added another user. Nothing out of the ordinary that I could tell.

Then, after a couple of hours of usage, it consistently got stuck during boot.