Persistent Error when Generating SkinMould

Hello! My name is Michael, I am an undergrad student currently doing a senior research project that involves the use of 3DSlicer. It is a great application, however when I try to generate a skin mould to generate a model for 3d printing, I get the same error no matter what parameters I change. I have followed the PerkLab instructions multiple times but to no avail. I have attached a screenshot of my most recent attempt, including the error that wont seem to go away no matter the changes. Any help is much appreciated thank you!