"Form New Assembly" triggering default template error

When I do a "Form New Assembly" on a part in an assembly, I get the following error:

"The default templates are not valid.  The problems can be resolved by correcting the default templates under the options dialog.  Do you want to continue with a blank template?"

What is the procedure for correcting / preventing this?  As far as I can tell, all of my file locations are correct.

Thanks for any help, as always.

SolidworksAssemblies