How to run Whiteboard on Univention Corporate Server

[idominiki]

Hi Team!

We're running Nextcloud from UCS AppCenter on Univention Corporate Server.

On the UCS System, I created a docker container, which runs the whiteboard server. After I created an apache config, the server runs locally on 127.0.0.1:3002

From inside the Nextcloud App Container I can successfully curl https://ourucsdomain.de/whiteboard and got "Excalidraw collaboration server is up :)"

I set both config values via occ command.

If I want to enable the App, I got error "Error: This app cannot be activated because it makes the server unstable."

What is wrong in my configuration?

Thanks!
Dominik