Kendala Upgrade Ubuntu server - problem snapd

[Max Alpha]

#ask

Saya mau upgrade Ubuntu server 14 LTS. Sudah sukses naik ke 16 LTS.
Saat mau di upgrade lagi ke 18 LTS, muncul error berikut

alpha@nautic:~$ sudo apt upgrade
Reading package lists... Done
Building dependency tree      
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
  linux-generic-lts-xenial linux-headers-3.19.0-80 linux-headers-3.19.0-80-generic
Use 'sudo apt autoremove' to remove them.
The following packages will be upgraded:
  snapd
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 standard LTS security update
Need to get 0 B/21.1 MB of archives.
After this operation, 37.2 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Selecting previously unselected package snapd.
(Reading database ... 147495 files and directories currently installed.)
Preparing to unpack .../snapd_2.48.3_amd64.deb ...
Failed to stop snapd.socket: Unit snapd.socket not loaded.
dpkg: warning: subprocess old pre-removal script returned error exit status 5
dpkg: trying script from the new package instead ...
Failed to stop snapd.apparmor.service: Unit snapd.apparmor.service not loaded.
Failed to stop snapd.core-fixup.service: Unit snapd.core-fixup.service not loaded.
Failed to stop snapd.failure.service: Unit snapd.failure.service not loaded.
Failed to stop snapd.recovery-chooser-trigger.service: Unit snapd.recovery-chooser-trigger.service not loaded.
Failed to stop snapd.seeded.service: Unit snapd.seeded.service not loaded.
Failed to stop snapd.snap-repair.service: Unit snapd.snap-repair.service not loaded.
Failed to stop snapd.snap-repair.timer: Unit snapd.snap-repair.timer not loaded.
Failed to stop snapd.socket: Unit snapd.socket not loaded.
Failed to stop snapd.system-shutdown.service: Unit snapd.system-shutdown.service not loaded.
dpkg: error processing archive /var/cache/apt/archives/snapd_2.48.3_amd64.deb (--unpack):
 subprocess new pre-removal script returned error exit status 5
Errors were encountered while processing:
 /var/cache/apt/archives/snapd_2.48.3_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
alpha@nautic:~$

Ini cara ngatasinya bagaimana ya?
Aplikasi snap-nya tidak bisa di run, selalu error socket tdk bs runing.