Unable to contact snap store

I installed Ubuntu 18.04 yesterday. Today I tried to install micro editor through snap, but it doesn't work. Any command like this sudo snap install hello-world freezes for a minute and I receive

error: unable to contact snap store

Is there some problem with the snap store or is it because I couldn't connect to it from my network? How could I check that?

Seems there might be a problem with the snap store this morning. Occasionally I get a successful return.

➜  ~ sudo snap find nextcloud
Name                Version           Developer     Notes  Summary
nextcloud-client    2.3.3+gitab40efe  nextcloud     -      Nextcloud Desktop Client
nextcloud-port8080  1.01              arcticslyfox  -      Nextcloud Server
nextcloud-nextant   11.0.0snap3       rmescandon    -      Nextcloud Server + search support
nextcloud           13.0.2snap1       nextcloud     -      Nextcloud Server - A safe home for all your data
cashbox-nextcloud   11.0.2snap2       cashbox       -      Nextcloud Server for www.cashBOX.plus
qownnotes           18.05.2           pbek          -      Plain-text file notepad with markdown support and ownCloud / Nextcloud integration
spreedme            0.29.5snap1       nextcloud     -      Spreed.ME audio/video calls and conferences feature for the Nextcloud Snap
solr                0.1               rmescandon    -      Starts up solr as forking daemon
mdns-hostname       0.0.1             welike        -      mDNS mini-daemon to published hostname.local
➜  ~ sudo snap find nextcloud
error: unable to contact snap store
➜  ~ 

I got the same error just now. A solution that worked for me was:

in terminal:

$ killall snap-store

Then the snap connection was back