Netflows from Cisco ASAs?

I am attempting to use Real-Time NetFlow Analyzer to receive NetFlow from a Cisco ASA (running version 9.6(3)1).   I have supplied the SNMP credentials for the ASA in the RTNFA tool and it displays the interfaces and statistics.    However, no matter which interface I select to start the flow capture for I get an error message that says "NetFlow is not detected on the selected interface".  I have used Wireshark on this machine to validate that I am seeing CFLOW packets (UDP/2055) from the ASA.

Based on another thread I found here I have tried removing/changing the SNMP credentials in RTNFA, but that has not helped.   The version of RTNFA I am running is 10.8.0.5.

Any help with getting this working would be appreciated.

Thanks,

Scott