you should have a head editable region, this will be used for the css and script code that is added to the page between the head tags.
a default template includes the following editable regions:
doctitle
head
you should keep these editable regions in place, and add at least a main content editable region
See the "Using Design Extender and Data Bridge's Theming Engine" video in the data Bridge section of our youtube channel:
webassist