Object reference not set to an instance of an object.

I am getting this error Object reference not set to an instance of an object. when I run a form which shows the Crystal Report after button click.
My Button Click Event code is:

Data_Conn DC = new Data_Conn(Application.StartupPath);
            button1.Enabled = false;
            button1.Text = "Openning..";
           
            try
            { 
                Application.DoEvents();
                if (checkBox1.Checked)
                {
                    DC.SelectSta("select comName,iType,iName,(qty & ' ' &  unit) as qtyU,mrp,sealBscVATrs,unitPri from StockDetails sd,ItemsTbl it where it.iCode=sd.iCode;", "StockDetails");
                }               
                else
                {                   
                    button1.Text = "Report";
                    button1.Enabled = true;
                    return;
                }
                if (DC.getDataSet.Tables["StockDetails"].Rows.Count > 0)
                {
                    //MessageBox.Show("Working");

                    StockDataSet SDS = new StockDataSet();
                    DC.getAdapter.Fill(SDS);
                    StockReport StR = new StockReport();
                    StR.SetDataSource(SDS.Tables[1]);
                    StR.Refresh();
                    showReport SR = new showReport();
                    SR.crystalReportViewer1.ReportSource = StR;
                    SR.crystalReportViewer1.Refresh();
                    
SR.MdiParent = this.MdiParent;
                    SR.Show();                    
                }
                else
                {
                    MessageBox.Show("Items not Found!!", "Winform App", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                }

The interesting thing is, when I run in debugging mode(F11) then it will show the records in report(no error), but when I run without debugging mode(F5) then it will give that error...
the error show the code which in Program.cs file :

Application.Run(new Form1());

the source of this error is: CrystalDecisions.Windows.Forms(I checked it from view details).

Please Help me..

Thanks in advanced...
Regards
Jayanta.

Tags: C# (C# 4.0), Windows Forms, CrystalReports