To Create The Business Chart I Referred the Link "suvidhablogpost.wordpress.com/.../dynamics-nav-2013-drill-down-on-business-charts" But It Gives the Dotnet Error in below image

Can You Please Help Out that issue. Thanks in Advance

This is My Code Unit Code

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Documentation()

OnRun()

GenerateDataInventorybyLoc(VAR BusinessChartBuff : Record "Business Chart Buffer";ItemNum : Code[10])
WITH BusinessChartBuff DO BEGIN
  Initialize;

  AddMeasure('Inventory',1,"Data Type"::Decimal,"Chart Type"::Column);
  SetXAxis('Location',"Data Type"::String);
  Query1.SETRANGE(Query1.Item_No,ItemNum);
  
  ItemNo:=ItemNum;//
  i:=0;
  J:=0;//
  Query1.OPEN;
  WHILE Query1.READ DO BEGIN
    i += 1;
    J+=1;
    BusinessChartBuff.AddColumn(Query1.Location_Code);
    SetValue('Inventory',i-1,Query1.Sum_Remaining_Quantity);
  LocCode[J]:=Query1.Location_Code;//
END;
Query1.CLOSE;
END;

OnDataPointClicked(VAR BusChartBuff : Record "Business Chart Buffer")
DrilldownLocInv(LocCode[BusChartBuff."Drill-Down Measure Index"+1]);

DrilldownLocInv(LocCode : Code[10])
ILE.SETRANGE("Item No.",ILE."Item No.");
ILE.SETRANGE("Location Code",ILE."Location Code");
PAGE.RUN(PAGE::"Item Ledger Entries",ILE);


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This is My Chart Page Code

LOCAL UpdateChart()
ItemQtyLocationWise.GenerateDataInventorybyLoc(BusinChartBuff,"No.");
BusinChartBuff.Update(CurrPage.Chart);

Chart::DataPointClicked(point : DotNet "Microsoft.Dynamics.Nav.Client.BusinessChart.BusinessChartDataPoint")
BusinessChartBuffer.SetDrillDownIndexes(point);
ItemQtyLocationWise.OnDataPointClicked(BusinessChartBuffer);

Chart::DataPointDoubleClicked(point : DotNet "Microsoft.Dynamics.Nav.Client.BusinessChart.BusinessChartDataPoint")

Chart::AddInReady()
UpdateChart;