If you get an error "Unable to connect", most of the time it means that the server is unreachable and does not necessarily mean that it is offline.
- Verify that the server your trying to connect to is online
- Verify your server address to be sure you have the right port and server address.
- Verify the address or port field to be sure there are no spaces or unwanted caracters
- In some cases firewalls or anti virus can block the communication with the server, click here for more informationa (Anti-Virus and Firewall related issues).