server not running on Win11 Pro

I started the content server on port 8080.
I tried to connect from the same machine that the server is on.
http://127.0.0.1:8080/
http://192.168.1.135:8080/

I get: Failed to communicate with "/interface-data/init?1741806708971", with status: [500 (error)] Internal Server Error

I disconnected from the Internet and disabled the firewall, didn't help.

I used to have this running on Win10 Pro.