You are syncing on the Android device and receive the following error message:

Last sync result:

Syncing finished with error: Username [HHC Username]: Server is busy/locked

This error message indicates that there is already a part of Handheld Contact syncing.  Since there are two pieces to the syncing process, the PC/server application for Handheld Contact is already in the process of syncing to our HHC Servers.  If one application (PC or device) is syncing then the other piece will be locked out during the syncing process. Only one end (PC or device) can sync with our servers at a time.  Once the synchronization completes, then go back and try syncing again.

 
If you continue to have this error, please go to the Handheld Contact app on the PC/server to determine the status and restart service if needed. Click HERE for more info.

Also see this article for more information about Handheld Contact and the syncing model.