Object reference not set to an instance of an object when calling a function - vb.net

Question

I call the function GetDataTable and when it gets to the return line, I get the error message:
Object reference not set to an instance of an object.
Dim DB As New DBConn
Dim gd As New DataAccess.GetData
Dim DT As New DataTable
Dim repotid1 As Decimal = 1150
Dim startdata1 As DateTime = "6/1/2012"
Dim EndDate1 As DateTime = "6/12/2012"
Dim StartDate3 As DateTime = "11/1/2011"
Dim Enddate3 As DateTime = "5/1/2012"
Dim sql1 As String = String.Format("EXEC [dbo].[usp_GetReportData_All] #ReportID=N'{0}', #StartDate=N'{1}' #EndDate=N'{2}', #StartDate2=N'{3}' #EndDate2=N'{4}'", repotid1, startdata1, EndDate1, StartDate3, Enddate3)
DT = DB.GetDataTable(sql1)
Public Class DBConn
Dim gd As New DataAccess.GetData
Public Function GetDataTable(ByVal sql As String) As DataTable
Dim _appID As String = "IS"
Dim _transID As String = "MSSQL01"
Return gd.getDataTable(_appID, _transID, sql) 'I get the error message here
End Function
End Class
Updated. I'll see if I can update with the DataAccess.GetData code. I didn't originally put it in there because our shop use it all the time and have no issues with it.

Answer 1

Without seeing what's in gd.getDataTable, there's not a lot we can do to help you. What kind of application are you writing that is calling this function? Can you put a breakpoint on that line in the editor and step into it to see where the error is occurring? Otherwise, do you have access to the DataAccess.GetData code? If so, you would get a lot more information from it if you threw the original exception without destroying the stack trace:
BAD!!!!
Try
'your code
Catch ex As Exception
Throw New Exception(ex.Message)
End Try
GOOD:
Try
'your code
Catch ex As Exception
Throw
End Try