crossed red line in C# Winform and hangs application

Question

Dear Sir,

 

My winform application showing a error. see the screenshot below:-

 

This error occurs once in a day when i running the application.

 

Here i pasting my c# code

try
{
if (FrmAdvSrchObj == null)
{
FrmAdvSrchObj = new FrmBankAdvanceSearch();
FrmAdvSrchObj.FormClosing += frmAdvSrchObj_FormClosing;
FrmAdvSrchObj.ShowDialog();
}
}
catch (Exception ex)
{
RadMessageBox.Show(ex.Message + "\nDash Board: 051", "CollectPlus - Dashboard", MessageBoxButtons.OK,
RadMessageIcon.Error);
}

Kindly reply with a solution.