I\'m migrating our SignalR-Service to the new AspNetCore.SignalR (2.1 preview) and now I get problems with CORS. I will never access the service from the same origin, so I n
I solved the problem.
The client-package and the server-package were not in the exact subversion state. It was 2.1-preview3210 and 2.1-preview3209 (example numbers).
The server-package is published to the nuget feed frequently but the client-package (npm) not. So I cloned the latest git repo by myself and build the libs and it works.
You will not have the problem anymore, the client-package is now up-to-date.