DataSet does not support System.Nullable.

Good day sir. i am design my project with asp.net with mvc technology. i use crystal report for visual studio (CRforVS_13_0_15) to design my report. When i try to preview my report i have a message "DataSet does not support System.Nullable<>." when i add the datasource to my crystal report document (

Line 488: rptH.SetDataSource(model);

). i declare model as a list of object like this : "List<object> model = new List<object>();"

i am using C# language.

Please somebody can help me to understand what happend and help me to have a solution.

Thank