NOTE: VCF Operations for Networks was formerly named Aria Operations for Networks (AON), and prior to that was named vRealize Network Insight (vRNI).
VCF Operations for Networks
To fix this issue enable Netflow on the added vCenter Datasource from within VCF Operations for Networks GUI.
The documentation to configure and use IPFIX with vCenter Servers can be found at Add VMware vCenter Server-To configure and use IPFIX