Cannot register a new Server in Work group Manager

Hello PTC Team.

For some reason I am not able to register a new Server in Work group Manager.
All Windchill services are up and running and I am able to login to Windchill as well.
I get an error: "Browser Service is unavailable.

Environment:
Windchill Release: 12.0.2.0
windchill 2.2.1 REST Services
windchill projectlink 12.0.2.0
windchill pdmlink 12.0.2.0

Would you please help?
Thanks
Laszlo