It appears that you are trying to measure a dc, low frequency,
quantity. What was the minimum frequency you defined in your
s-parameter file? Did you define a dc value? If the minimum
frequency is 100MHz and you are trying to get a dc value then
did you do anything to improve the dc value estimation, for
example, set dcextrap? More/any detail about what you are doing
would be helpful.

Which version of the simulator are you using? What options have you set on the nport (ideally show the line in the input.scs so we can see all the options).

Kind Regards,

Andrew.