Receiving the error: snapd.snap-repair.service is a disabled or a static unit, not starting it

I also had the same problem and I solved it like this:

sudo fuser -vki /var/lib/dpkg/lock
sudo apt purge snapd
sudo dpkg --configure -a
sudo apt update
sudo apt upgrade
sudo apt dist-upgrade
sudo apt install snapd

Workaround for Ubuntu 18.10:

sudo dpkg -r snapd gnome-software-plugin-snap
sudo apt update
sudo apt full-upgrade