"gtk-warning **: cannot open display: :0" while trying to launch ElectronPlayer
Solution 1:
Try updating your snap package.
To update snap package follow these steps from Zygmunt's answer on How can I update all Snap packages?
sudo snap refreshWill do this. It is part of
snapd2.0.8, which landed 2016-06-13 inxenial-updates.snap refresh --listOnly lists the updates without refreshing the packages.
snap info <snap name>Can show which versions are available for a particular package.