FYI - this happened when running thru VS when the solution is located in this path
C:\Users\myuser\Documents\Visual Studio 2010\Projects\nopCommerce 2.00 BETA Revs\nopCommerce_3d33c49acebe\src
I copied it into c:\src, and it worked OK.
Edit Discount Details - Sample Discount With Coupon Code
Discount requirement type: Customer has previously purchased.... [either one]
System.IO.PathTooLongException was unhandled by user code
Message=The specified path, file name, or both are too long. The fully qualified file name must be less than 260 characters, and the directory name must be less than 248 characters.
public abstract class ThemeableBuildManagerViewEngine : ThemeableVirtualPathProviderViewEngine
...
return BuildManager.GetObjectFactory(virtualPath, false) != null;
virtualPath =
"~/Views/DiscountRulesPurchasedOneProduct/Nop.Plugin.DiscountRules.PurchasedOneProduct.Views.DiscountRulesPurchasedOneProduct.Configure.cshtml"