9. Inter process communication error.
Occurs if DP4 is shut down while a DP4 program is running. Non-recoverable. A program should always terminate if it encounters this error, as the DP4 system cannot be reloaded after this type of error until all DP4 programs have terminated.
DP4 programs should listen for the message that is broadcast when the DP4 system is shutting down, and close gracefully. This will generally happen automatically for DP4 programs that use the terminal manager.
On Windows platforms, if there is an additional error code, it will correspond to a Loader Error message, most commonly 86, which indicates that the DP4 system believes that one or other of the server components loaded as part of the DP4 service has died, or that the DP4 system has been shutdown.