trial period for netflow analyzer is just 1 hour?

trial period for netflow analyzer is just 1 hour?

I installed the netflow analyzer 9.7 today for evaluation.    From the dashboard, all the information about the netflow from one of my test router has been fine for 1 hour, then all the interface speed became 0.
 
I thought the trial period for netflow analyzer is 30 days.
It worked for just 1 hour.
 

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