Same problem. I am running PI4 openHAB 2.5.9 Release Build, and have access to the files via Easy Access on Zdive. I am running the demo program and see and can edit my config code and saved, but expected to see the changes reflected on the Main Menu when I opened I pressed the openHAB button on the top bar. Just got an empty window.
I have the following message on the bottom window under the tab “Output” - openHAB server:
Error - 1:58:49 PM] Connection to the server is erroring. Shutting down server.
Seems I am missing a visual studio configuration variable setting.