Error getting authority: Error initializing authority: Could not connect: No such file or directory (g-io-error-quark, 1)

The reason for this error was an entry in /etc/fstab that pointed to partition UUID that was no longer existing (after I reformatted one of the hard drives).

The solution was to remove the fstab entry.

NOTHING AT ALL in the error message indicates what might be the cause of the error, neither does calling journalctl as systemd suggests.

Browsing the internet revealed that the exact same error can be produced in several different situations. Take a look at 'starting version 219' bug after the 15.04 update for other causes. Googling for the phrase returns few other possible causes.

Hope it helps anyone who stumbles upon this cryptic error.

One of your mount points is failing. View the log to see which one.

journalctl -xb

Search the log for the word mount by typing /mount Enter and n to find the next entry. You'll eventually see an error in the log. Take note of the mount point.

Edit /etc/fstab with your favourite text editor.

vim /etc/fstab

Add the option nofail to the failing mount point or all the mount points that are not required at boot time.

# <file system>                           <mount point>         <type> <options>            <dump><pass>

UUID=005c216a-012e-440c-8e92-c955cbc48c34 /mnt/notrequired      btrfs  rw,noatime,nofail    0     1

Reboot

systemctl reboot

It's worth stressing that any failed fstab mount will cause full system failure with the meaningless error message. That includes cd, dvd, swap, mapper and data partitions. Put the nofail option on to every line in /etc/fstab that you think might not be available at any boot time, even apparently otherwise unimportant ones.

Unfortunately some bad decisions were made with systemd including a lack of fault tolerance and a lack of actionable error messages. It's not at all clear that the advantages of systemd outweigh the disadvantages.