Cannot Communicate with Server: Post Http: //Localhost/V2/Snaps/Discord: Dial Unix /Run/Snapd. Socket: Connect: Connection Refused

Unmask it:

sudo systemctl unmask snapd.service

Enable it:

sudo systemctl enable snapd.service

Start it:

sudo systemctl start snapd.service

I've been having the same issue for some time now.
I solved the issue by uninstalling snap and then reinstalling it:

$ sudo apt autoremove --purge snapd
$ sudo apt install snapd

This issue came to me because i changed permission to 777 I searched every where and I find only this solution is best sudo apt-get purge snapd sudo apt-get install snapd

This issue came when i was trying to install spotify on my kali machine using snap "snapd" so this issue can be solved with the following commands on the terminal Firstly install snap **$ sudo apt install snapd** or remove it by **$ sudo apt autoremove --purge snapd** then install it again Then enter the following commands

$ sudo systemctl enable snapd`
$ sudo systemctl start snapd 
$ sudo snap install spotify

you should be able to download spotify on your kali/ubuntu Machine

This solution finally worked for me with a slight addition

sudo apt autoremove --purge snapd sudo apt install snapd

On purging /var/snap/firefox would not purge , it was marked as a read only

I renamed the whole snap firefox folder and repeated the purge until I had a clean purge

Finally the snapd install went though as a clean install I checked with journalctl -xeu snapd.service