Please go to the Manage Palette option of the hamburger menu in the upper right of the editor. Then type in dashboard and tell me what shows up.
It looks like you have installed the node dashboard-evi and are not using `node-red-dashboard' (you can't use two dashboaed nodes or it causes conflicts'. This probelm has to do with that node.
The bad news is the GitHub page for that node no longer exists so you can't report this issue to the author.
My suggestion is to remove that node and install node-red-dashboard if it is not already installed.
