You might want to check and verify that the CUE module has booted and is accessible before you try any configuration through CCA. It can hose up your config if you try to proceed too quickly. A good rule of thumb I always follow when using CCA is to set back to factory defaults and upon rebooting go away and do something else for 10-15 minutes while the system boots, phones update, CUE initializes, etc...
If you issue the command service-module integrated-Service-Engine 0/0 status what output is returned?
Configure Multicast Paging on the Cisco IP Phone 7800 Series or 8800 Series Multiplatform Phone
The Cisco IP Phone 7800 and 8800 Series Multiplatform Phones provide voice communication over an Internet Protocol (IP) network...
Add Call Park on a Cisco 7800 or 8800 Series Multiplatform Phone Key Expansion Module
Call park allows the user of the phone to put an incoming call on hold so that the call can be retrieved on another phone. A call is park...