This error means that the protected application on the client has not received a reply from DinkeyServer.

The extended error code is a socket error which could indicate the problem.

This could be happening because a firewall is blocking communication on the client or the server.

Alternatively it can be caused by a program such as an anti-virus blocking network communication on the client or the server.

Obtaining the DinkeyServer log file can be useful. In particular it is helpful to know if DinkeyServer is logging an error at the same time as the protected program on the client is giving an error.