I have installed the final version of Crystal Reports for Visual Studio 2010. I created a new ASP.Net project, saved it, closed it, and then came back to it later. I was prompted to convert the project because of an out of date version of Crystal Reports. But I just created the project...how can the version already be out of date? Also, once the conversion is complete the CrystalReportViewers error stating "Unable to cast object of type 'CrystalDecisions.Web.CrystalReportViewer' to type 'CrystalDecisions.Web.CrystalReportViewerBase'. I am using .NET Framework 4.0 for other . How to solve this problem?.please help me.