Boot failure after High Sierra Update

Originally I updated my 2012 Mac Mini to High Sierra and quite frankly... it broke! I did a full recovery and an install of High Sierra from scratch and system has ran fine.

I have however since applied the 10.13.1 update from App Store onto it... and it's failing to boot.

Black screen with Apple logo at boot, won't go any further than the 100% thermometer.

Went into verbose mode, and the following is showing:

Synced /var/db

Warning: couldn't block sleep during cache update

Warning: proceeding w/o DiskArb

/dev/disk1 on / (hfs, local, journaled)

bash: /etc/rc.server: No such file or directory

tzinit: New update not compatible or older version: 2017c.1.0 vs 2017c.1.0: No such file or directory

Date/Time localhost com.apple.xpc.launchd[1] <Notice>: Early boot complete. Continuing system boot.

pci pause: SDXC

Waiting for DSMOS...

And there it hangs.

I really don't want to have to rebuild this Mini again!