CMG GroupWise to Exchange error, "This request operation sent to net.pipe://localhost/pipe2/GroupWiseAccess did not receive a reply within the configured timeout (00:04:00)." (4343947)

When running a Coexistence Manager for GroupWise (CMG) Exchange to GroupWise Directory Connector, the following error may occur in the logs:

Synchronization steps aborted. Details: This request operation sent to net.pipe://localhost/pipe2/GroupWiseAccess did not receive a reply within the configured timeout (00:04:00). The time allotted to this operation may have been a portion of a longer timeout. This may be because the service is still processing the operation or because the service was unable to send a reply message. Please consider increasing the operation timeout (by casting the channel/proxy to IContextChannel and setting the OperationTimeout property) and ensure that the service is able to connect to the client. I have never seen this before.