Error installing snapd on Mint 18

I have a fairly clean and up to date Mint 18 install. Install snapd gives errors…

Job for snapd.seeded.service failed because the control process exited with error code. See "systemctl status snapd.seeded.service" and "journalctl -xe" for details.

What’s the problem here?

alan@mint18 ~ $ sudo apt install snapd
[sudo] password for alan: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  squashfs-tools
The following NEW packages will be installed
  snapd squashfs-tools
0 to upgrade, 2 to newly install, 0 to remove and 0 not to upgrade.
Need to get 13.6 MB of archives.
After this operation, 80.2 MB of additional disk space will be used.
Do you want to continue? [Y/n] 
Get:1 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 squashfs-tools amd64 1:4.3-3ubuntu2.16.04.1 [104 kB]
Get:2 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 snapd amd64 2.32.9 [13.5 MB]
Fetched 13.6 MB in 5s (2,668 kB/s)
Selecting previously unselected package squashfs-tools.
(Reading database ... 198212 files and directories currently installed.)
Preparing to unpack .../squashfs-tools_1%3a4.3-3ubuntu2.16.04.1_amd64.deb ...
Unpacking squashfs-tools (1:4.3-3ubuntu2.16.04.1) ...
Selecting previously unselected package snapd.
Preparing to unpack .../snapd_2.32.9_amd64.deb ...
Unpacking snapd (2.32.9) ...
Processing triggers for man-db (2.7.5-1) ...
Setting up squashfs-tools (1:4.3-3ubuntu2.16.04.1) ...
Setting up snapd (2.32.9) ...
Job for snapd.seeded.service failed because the control process exited with error code. See "systemctl status snapd.seeded.service" and "journalctl -xe" for details.
snapd.seeded.service couldn't start.
snapd.snap-repair.service is a disabled or a static unit, not starting it.
alan@mint18 ~ $ uname -a
Linux mint18 4.10.0-38-generic #42~16.04.1-Ubuntu SMP Tue Oct 10 16:32:20 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
alan@mint18 ~ $ snap version
snap       2.32.9
snapd      2.32.9
series     16
linuxmint  18.3
kernel     4.10.0-38-generic
alan@mint18 ~ $

alan@mint18 ~ $ systemctl status snapd.seeded.service
● snapd.seeded.service - Wait until snapd is fully seeded
   Loaded: loaded (/lib/systemd/system/snapd.seeded.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Wed 2018-06-20 16:25:08 BST; 47s ago
  Process: 2881 ExecStart=/usr/bin/snap wait system seed.loaded (code=exited, status=1/FAILURE)
 Main PID: 2881 (code=exited, status=1/FAILURE)

Jun 20 16:25:03 mint18 systemd[1]: Starting Wait until snapd is fully seeded...
Jun 20 16:25:08 mint18 snap[2881]: error: cannot communicate with server: Get http://localhost/v2/snaps/system/conf?keys=seed.loaded: dial unix /run/snapd.socket: connect: no such file or directory
Jun 20 16:25:08 mint18 systemd[1]: snapd.seeded.service: Main process exited, code=exited, status=1/FAILURE
Jun 20 16:25:08 mint18 systemd[1]: Failed to start Wait until snapd is fully seeded.
Jun 20 16:25:08 mint18 systemd[1]: snapd.seeded.service: Unit entered failed state.
Jun 20 16:25:08 mint18 systemd[1]: snapd.seeded.service: Failed with result 'exit-code'.
alan@mint18 ~ $ 


alan@mint18 ~ $ journalctl -xe
-- Subject: Unit UNIT has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit UNIT has finished shutting down.
Jun 20 16:26:05 mint18 systemd[1168]: Stopped target Basic System.
-- Subject: Unit UNIT has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit UNIT has finished shutting down.
Jun 20 16:26:05 mint18 systemd[1168]: Stopped target Sockets.
-- Subject: Unit UNIT has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit UNIT has finished shutting down.
Jun 20 16:26:05 mint18 systemd[1168]: Stopped target Paths.
-- Subject: Unit UNIT has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit UNIT has finished shutting down.
Jun 20 16:26:05 mint18 systemd[1168]: Stopped target Timers.
-- Subject: Unit UNIT has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit UNIT has finished shutting down.
Jun 20 16:26:05 mint18 systemd[1168]: Reached target Shutdown.
-- Subject: Unit UNIT has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit UNIT has finished starting up.
-- 
-- The start-up result is done.
Jun 20 16:26:05 mint18 systemd[1168]: Starting Exit the Session...
-- Subject: Unit UNIT has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit UNIT has begun starting up.
Jun 20 16:26:05 mint18 systemd[1168]: Received SIGRTMIN+24 from PID 3044 (kill).
Jun 20 16:26:05 mint18 systemd[1]: Stopped User Manager for UID 108.
-- Subject: Unit user@108.service has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit user@108.service has finished shutting down.
Jun 20 16:26:05 mint18 systemd[1]: Removed slice User Slice of lightdm.
-- Subject: Unit user-108.slice has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit user-108.slice has finished shutting down.