Product Family: Act!
Product: Act! Pro, Act! Premium, Act! Premium (access via web), Act! Premium Cloud
Integration: Act! emarketing
This can be because the template was imported into Act! emarketing, rather than created from an existing template. This is functioning as designed
Rather than trying to edit the imported template from within the Act! emarketing template editor, it will be necessary to edit the template from an HTML editor, such as the one that was used to create the template to begin with, then import it back into Act! emarketing.