I am using Crystal reports viewer on a normal ASP.NET aspx page in an MVC3 application. In a controller action I am simply redirecting to the aspx page and the report shows
I had the same problem, but fortunately I have some experience with Crystal Reports.
You just need to change the Web.config, because the "path" attribute is set to site root. It will work if you open the url in browser and remove the ReportWebForms from it.
Actually I've just added 2 more lines of configuration:
And finally you have to add an ignore rule the route for MVC application:
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.IgnoreRoute("{resource}.aspx/{*pathInfo}");
// Here is added new ignore rule
routes.IgnoreRoute("Reports/{resource}.aspx/{*pathInfo}");
In my case I have a folder named Reports where the .aspx file is placed. I guess you should change this to ReportWebForms in your case.