Thank you for your post.
To make sure there wasn't a problem with the download, I also downloaded and installed FileMaker Pro 11 Advanced. I am able to open every one of the Template files. For example,
FileMaker Pro 11 Advanced -> English Extras -> Templates -> Business - Finance -> Expense Report.fp7
Double-clicking on this file opens in FileMaker Pro 11 Advanced.
Are you running this on Windows or Mac? What version of the OS? I will try here to replicate your environment.