Nevermind, it seems to be related with the previous “npm install” attempts that failed due to the missing prerequisite.
Npm apparently didn’t repeat these parts correctly. I removed the whole folder again and started from scratch. With the prerequisites in place and npm install working on the first try, Volumio starts up fine.
However, it says it opens port 3000 for listening but calling it results in “too many redirects”.
It also doesn’t answer to websocket requests from the UI project on port 80: 192.168.178.45/socket.io/?EIO=3