"...invalid Heating Energy Input Ratio Modifier Function of Low Part-Load Ratio Curve Name = VRF SYSTEM HEATIINGEIRLOWPLR 13 has out of range value. Curve minimum value of X = 0.500 must be <= Minimum Heat Pump Part-Load Ratio =0.250." The error file tells you what is wrong - your curve is under-defined. The heat pump can go do to a part load ratio of 0.250, but one of your curves is only specified down to 0.500. So it can't get curve values for X values between 0.25 and 0.5. Try to regenerate your equipment curves or find another source for them for the full range available to the equipment, in this case down to a part load ratio of 0.25.