Failed to map the path..."

When you create a new .NET Web application under a default Web site in IIS 7 (so the URL of your new Web application will be http://localhost/mywebsite, for example), you may encounter an error saying "Failed to map the path...".

To get rid of this error, make sure that the application pool of your new .NET Web application and the application pool of the default Web site are the same.  The following pictures show the cause of the error:

default_web_site

new_web_app

Change the application pool of the latter one to be the same of the first one solves the problem Angel