New Action on CommonController 'Not Found'

[PixelDevelopers]

So I've created a new Action on the CommonController in the SmartStore.Web Project. I have tried to make a call to the action, only no matter how I try I just get a Not Found error.

"System.Web.HttpException: 'Error executing child request for handler 'System.Web.Mvc.HttpHandlerUtil+ServerExecuteHttpHandlerAsyncWrapper'.'
A public action method 'Reviews' was not found on controller 'SmartStore.Web.Controllers.CommonController'."

//Controller Code
[ChildActionOnly]
public ActionResult Reviews()
{
return PartialView();
}

//Home Page Index.cshtml
Html.RenderAction("Reviews", "Common");

I have forced rebuild the solution - cleaning etc, I just can't get it to work. If I examine the DLL Output after build, the action exists. Anyone had this issue or can advise?

[PixelDevelopers]

Seems it builds correctly, but when run, the files copied to AppData\Local\Temp\Temporary ASP.NET Files seem to be outdated / not copied properly.