The "Flow Supplied" field in the calculation summary is related to flow coming from a reservoir. If this is zero, it can mean a couple of things. First, there may not be a reservoir in the model. It is not possible to tell if that is the case here. Second, if there is a reservoir in the model and there is a pump connected to it, it can mean that the pump has a calculated status of Off. Basically, there would be no flow from the reservoir because there is no flow from the pump.
There are values for Flow Demanded and Flow Stored. This means that the demand in the system is being satisfied from a tank in the model.
More information on these fields can be found here: Calculation Summary: Flow Supplied, Flow Demanded, and Flow Stored.