Since we change the subnet mask of the secondary IPCC server, the service Cisco desktop Sync Service as stop.
I cannot find were in need to change the information to start again the service.
I have the same problem. I am using UCCX 5.02
Look in Cisco Unified CCX Serviceability, under Process Activation and look for the service Cisco Desktop Enterprise Service.
If this service is stop, try to start it from there and look if everything back to normal.