Forming Tool: This feature only works on sheet metal parts

Hi all,

I am currently making a progressive die strip and would like to add a form tool to the strip. I probably should have done this in the beginning because now I am going to have to add it to each configuration (step in the progression) I have for the part. Weird thing though, the from tool only is accepted on certain configurations. They all have the same sheet metal base flange and no solid extrusion, embosses. The error I am getting is 'This feature only works on sheet metal parts'. What would cause it to only recognize some configurations are sheet metal and others as not?

Thanks

SolidworksParts And Features