cant select post calibration monte carlo

I have calibrated the groundwater flow model manually. I want to quantify the uncertainty and sensitivity of the model. I'm not able to select post-calibration monte Carlo from the optimisation control window. anyone pls help? thank you.

Probably the current FePEST is missing some results. Typically, you will require to have a Jacobian matrix (*.jco file) computed from an Estimation run.

Regards, Carlos Rivera

ok thank you