Netflow on sub-interface cisco asa already defined error

[pro6151945]

We are having 2 ASAs connected over MPLS and the requirement is that, we need to monitor these interfaces using netflow. Our netflow logs are sent to 192.168.99.11 server. Netflow is already configured on outside interface on the ASA on one side and it has sub interface also. When i am trying to add netflow on the other sub-interface as well then i receive the below error:- 

ERROR: flow-export: destination with same IP already exists

Please assit, how can i add this sub-interface as well in the netflow configuration.

Thanks

[balaji.bandi]

Can you post relevant configuration for us to understand the issue?

[Marvin Rhoads]

You cannot add a second exporter to the same destination on a given device.