Hello H2Tran,
What you usually must know when designing heat exchanger, from thermohydraulic point of view, is:
1) Maximum allowable pressure drop for one or both fluids (depends on specific application).
2) Inlet and outlet conditions (p, T) of both fluids. The flow of utility fluid is calculated using heat balance equations. I'm assuming that compositions and physical parameters of both streams are known.
3) Any specific metalurgical, physical/chemical concern (fouling tendency, erosion, vibration, thermal stability etc.) - that is something that goes in further design steps.
HYSYS is not so good in heat transfer design applications. The latest version (now under the name UniSim Design - Honeywell trademark) is somewhat upgraded by certain AspenTech moduls, as I have heard. But I didn't have a chance to check it.
I hope this helps in your query.
Concerning the file you attached, please check your streams - names and stream allocation, compositions, pressures and temperatures.