Won't boot, ACPI PCC probe failed

After updating, my desktop machine will no longer boot. It shows the message ACPI PCC probe failed, starting version 219 and then stops in with a command prompt and some text about it being in Emergency Mode.

There are already numerous questions on this, but only this one appears to have an answer. The accepted and upvoted answer does not actually give a solution; it says that the message is harmless and can be ignored.

Since my PC will no longer boot, I am finding it difficult to ignore. What do I need to do?

Edit: There is a list of startup tasks, all showing 'OK', the last being Show Plymouth Boot Screen...

And below that is the Welcome to emergency mode! prompt.

Viewing the system logs with journalctl -xb gives a vast amount of output - what should I be looking for?

The output of systemctl --failed is

âùÅ home-carl-Music.mount  loaded failed failed /home/carl/Music

and my other NFS shares are also listed.

I have edited them out of /etc/fstab and the machine now boots.