When I tried to mold a mold on a shell model, I couldn't. Do I have to convert any models? Excuse me, but could you tell me who this is?

I want to create a mold with the Cavity command, but when I check it after the cavity is run,
The type could not be created.

Please let me know how to solve it if anyone knows it well.

SolidworksModeling And Assemblies