How to slove out_of_Memory_Exception error in asp.net C#

public partial class MF_168 : System.Web.UI.Page

{

ReportDocument Rptdoc = new ReportDocument();

protected void Page_Load(object sender, EventArgs e)

{

SqlConnection con = new SqlConnection();

con.ConnectionString = ConfigurationManager.AppSettings["Connection"];

SqlCommand cmd = new SqlCommand("select Plant_Name from Format_Mechanical_List_Of_Misc_Equipments where id=1", con);

SqlDataAdapter da = new SqlDataAdapter(cmd);

DataSet ds = new DataSet();

da.Fill(ds);

Rptdoc.Load(Server.MapPath("~/CR_Reports/Mechanical/MF-168.rpt"));

Rptdoc.SetDataSource(ds.Tables[0].Rows.Count);

CrystalReportViewer1.RefreshReport();

CrystalReportViewer1.ReportSource = Rptdoc;

ds.Clear();

ds.Dispose();

}

protected void Page_Unload(object sender, EventArgs e)

{

Rptdoc.Close();

Rptdoc.Dispose();

GC.Collect();

}

}

 

 i am loading crystal report in C# .this code build than not page load and direct show memoryException error.

my report is 32bit  .than selected 64 bit iis and build project .

 This line Show error => Rptdoc.SetDataSource(ds.Tables[0].Rows.Count);

 error => 'CrystalDecisions.CrystalReports.Engine.DataSourceException' occurred in CrystalDecisions.CrystalReports.Engine.dll but was not handled in user code '