Error 404 When Accessing PWA Site

Hi,

I have PWA installed with SharePoint 2013.

The main site is on port 80 and can be accessed by using server name 

e.g. : http://servername/ 

and also using the url which has been assigned

e.g. http://www.site.com

The PWA site can be accessed by using the server name 

e.g. : http://servername/PWA

but it cannot be accessed using the url

e.g. : http://www.site.com/PWA

The PWA uses the same web application as the main site and is this on the same default port 80.

AAM should be fine as the root site can be accessed from other machines and even the PWA site can be accessed using server name, it just cannot be accessed using the URL.

Thanks for your help in advance.