@sdetweil I was in the MMM-LAMetro directory. I used the “node install” command from the readme. Forgot the correct command was “npm install”. No issues once I used that command.

With the help of another User on Github we found out what was causing the error!
It was the sudo, that I mistakenly used to execute the script. Running the install as pi was the solution.

Hope this will help someone with the same problem. :)

Interesting. Could you give https://github.com/electron/electron-quick-start a try to see if that one works?