[phenixbb] Calculate F (model) + Calculate Map Correlation

Hi, I am trying to use phenix and I was trying to do the following: Take a PDB, generate a MTZ file using Calculate F (model) and lets call it native.mtz then change a few phi and psi values of the pdb (so its slightly different from the native), run Calculate F (model) model.mtz Now I tried to calculate the CC of the two MTZ using Calculate Map Correlation. I get the following: "Missing at least one map file or label" What am I doing wrong? Thank you, George