I'm running CUCM 9.0. I have Software CFB build-in which are added to MRG->MRGL-Device pool and Phones. but I can't use conference feature, the symptom is that the phone said "Conference" but return Fast Busy. Same as Meet Me. All of my phones are registering to same CCM server.
Update: the RTMT tells that The Resource is unavailable.
Can you help me to solve the problem?