On Free Trial license, Unlicensed flows mean that your network exports more than 500 fps limit. You should take into consideration both Processed and Unlicensed flows for your Commercial license.
On Commercial license, Unlicensed flows mean that your network devices are exporting more flows than your current Commercial license allows.These flows will not be processed and, therefore, information provided by them will not be included when creating and displaying traffic statistics. In this case, you should upgrade your Commercial license.