This may be due to one of the following reasons, related to the server computer:

1. The server is not running on the server computer. Make sure that you see a window titled "JIS Server" on the server computer.

   In case you don't see one, run it by clicking on the "JIS Server" icon, or by using the "Run Application" wizard, accessible from the "File" menu of the development environment.

2. The TCP/IP connection between the client and the server is not set up properly. You can verify that the server can reach the client this by running "ping CLIENT-NAME" on the server. If you don't know how to use "ping", you can ask your system administrator for help.

3. Port numbers problems: the client may be connecting to the wrong port number, or that port might be in use by another program on the server.

   The problem may be solved by changing the port numbers. Note that both port numbers should be at least 1024, and different from each other. After changing the communication settings you must restart the server.

   When looking for a free port number, you can see which ports are in use on the server computer by running "netstat". If you don't know how to use "netstat", you can ask your system administrator for help.