The virtual path XX maps to another application, which is not allowed.

I have copied one website to another folder and tried to run it in Visual Studio using IIS, but for some reason it is giving me a compile error in the following lines in the web.config file: ``` <add tagPrefix="QuickBuck" tagName="RecentlyModified" src="/Controls/RecentlyModified.ascx" /> <add tagPrefix="QuickBuck" tagName="Sitemap" src="/Controls/Sitemap.ascx" /> ``` There is also another line underneath them which doesn't error, making this even stranger: ``` <add tagPrefix="QuickBuck" tagName="Menu" src="/Controls/Menu.ascx" /> ``` The controls are there, why is this happening? The exact errors are like so: ``` The virtual path '/Controls/RecentlyModified.ascx' maps to another application, which is not allowed. The virtual path '/Controls/Menu.ascx' maps to another application, which is not allowed. ``` There isn't actually a line number next to the errors so I assume it is from the web.config. Please help this is driving me crazy!