Error Message When I Save a File as a Template

Hi,

I want to set up some files as templates I can easily access. 

When I do File > Save As Template, and then name the template file and click 'save', I get an error message: "Can't save the illustration. You do not have enough access privileges". 

Screenshot is below.

Does anyone know what is causing this, and how to correct it?

Thanks,

Paul.