Inroads inlet time of concentration computation error

Hello,

When I clicked on the flow tab for any of my inlets, I have noticed under the time of concentration computation the time to inlet, time from upstream as well as sum of C*A have zero Value. Why does these happen? And how do I resolve this issue. I will like to add that all inlets have areaS attached with c value . In addition, I have also attached the idf file and selected the proper storm event.

thanks 
Mah