Server sent events


i’m using this sse client to listen to events, but it seems like OpenHAB’s SSE is the only one not working.
I’ve tried it with different SSE Servers and they all work, but when i try it with OpenHAB’s SSE i get an exception:

System.Net.WebException: The remote server returned an error: (400) Bad Request.

Is the URL i’m using right?

What could cause this exception?