Messenger Client 3.0 Windows not starting

Hi Guys,

i installed the Messenger 3.0- The Server is running fine and if i use an old Client (2.2.0) or the skypro Kommunicator or the Android APP, it works. When i try to start the Windows 3.0 Client on different Systems it hangs while schowing Connecting to "Server:8300". I have no error message in the Log files.

Could you help me with this Problem?

Best Peter