Service Not Available in WebEx Connect

I came across this error message when trying to use either the softphone or deskphone control in WebEx Connect.  On the Phone tab, you will see an error message stating:

SERVICE NOT AVAILABLE
Your Communications Manager account is not configured correctly.  Please check your settings.  If you still have problems, contact your system administrator.

I made sure I had the latest CUCI Connect installed, then after quite a bit of troubleshooting including verifying the IP address and username and password of my CUCM account, phone and user association in ccmadmin, etc., I remembered I had recently installed the CUPC (Cisco Unified Personal Communicator) for troubleshooting a customer's network.  These 2 applications apparently conflict with each other.

Fix / Resolution / Workaround:

Uninstall the Cisco Unified Personal Communicator application.