This issue is has three main causes each being by a firewall blocking the necessary ports, lack of internet connection to the server, and/or a older version of Studiometry being used with a newer version.

CHECK FIREWALL AND INTERNET CONNECTION

This issue is sometimes caused by a Firewall blocking the necessary ports for Studiometry's networking capabilities.  Check to make sure your firewall allows access on ports 4465, 4466, and 9090.

In your Studiometry Preferences > Network tab, ensure that your server's IP address is available as an option.  If it is not, check your network set up and paths between computers.

CHECK YOUR STUDIOMETRY VERSION

Make sure all of your machines on the Studiometry network are running the same version of Studiometry.  

OTHER POSSIBILITIES

There are several other things that can cause you to have issues connecting to a server.

• It's possible the server's IP address changed but the client machine does not have the new IP address entered.
• The client machine or server machine could have Studiometry networking connections blocked by the system (the little window that appears asking if you want to allow networking connections when you first launch it) or by a third party application such as Little Snitch.
• If you have a local IP address entered to connect to the server and then you take the client machine out of the office, that IP address will no longer connect to the server.
• The server cannot accept incoming connections if it asleep
• The server software cannot process information if it is stuck in a state that pauses code from executing, such as with a menu selected or certain modal dialogs. We've worked on removing as many of these as possibly to avoid these situations.