CrystalDecisions.CrystalReports.Engine.DataSourceException: The report has no tables

Sir i am not able to create an object of my crystal report page in .aspx page(the one which is having crystal report viewer in it).

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Configuration;
using CrystalDecisions.CrystalReports.Engine;

public partial class cr : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
        DataSet1 ds=new DataSet1();
        SqlDataAdapter adapter=new SqlDataAdapter("SELECT UserName, WardNo, Password, ElectionId, Day, Month, Year, Gender, EmailId, Address FROM dbo.users",con);
        adapter.Fill(ds.viewcan);
        CrystalReport report=new CrystalReport();
         
        report.SetDataSource(ds);
        CrystalReportViewer1.ReportSource=report;
    }
}

the above code is giving following error

The report has no tables.

Exception Details: CrystalDecisions.CrystalReports.Engine.DataSourceException: The report has no tables. Source Error: 

Line 19:        // CrystalReport report=new CrystalReport(); Line 20:         CrystalReport report = new CrystalReport(); Line 21: report.SetDataSource(ds); Line 22:         CrystalReportViewer1.ReportSource=report; Line 23:     }