Not able to connect to Actional Diagnostics Activation Serve

Hi,

I installed Actional Diagnostics version(8.0.3.1). The Actional Diagnostic server also got started which I can see in system tray.But the Web Application page fails to launch with the message as mentioned below:

Welcome to Actional Diagnostics

Trying to establish a connection with activation server...

Sorry but we were unable to obtain a connection with the activation server.
Please check your internet connection and try again.

Try again

Any information on how to solve this issue would be of great help.

Thanks!