Exception with empty StackTrace

Question

We have a method which takes care for reporting unexpected errors.

Our handling code (vb.net 4.0):

    Private paUnhandledException As Exception

    Private Function GetMessage(Detailed As Boolean) As String
        Dim stackMsg, msg As String
        Dim ex As Exception = Me.paUnhandledException

        If Detailed Then
            stackMsg = ex.ToString()
        ElseIf (Not String.IsNullOrEmpty(ex.StackTrace)) Then
            stackMsg = ex.StackTrace
            Dim l As Integer = 0
            Try
                l = stackMsg.IndexOf(System.Environment.NewLine)
                If l > 0 Then
                    l = stackMsg.IndexOf(System.Environment.NewLine, l + 1)
                End If
                If l > 0 Then
                    l = stackMsg.IndexOf(System.Environment.NewLine, l + 1)
                End If
            Catch
                l = -1
            End Try
            If l > 0 Then
                stackMsg = stackMsg.Substring(0, l - 1)
            End If
        Else
            stackMsg = ex.ToString
        End If

        msg = String.Format("{1}{2}",ex.Message, stackMsg)
        Return msg
    End Function

Usually we receive reports similar to this:

Dynamic SQL Error SQL error code = -206 Column unknown PRINTING.INACTIVE At line 1, column 688

FirebirdSql.Data.FirebirdClient.FbException (0x80004005): Dynamic SQL Error SQL error code = -206 Column unknown PRINTING.INACTIVE At line 1, column 688 ---> Dynamic SQL Error SQL error code = -206 Column unknown PRINTING.INACTIVE At line 1, column 688 at FirebirdSql.Data.FirebirdClient.FbCommand.ExecuteReader(CommandBehavior behavior) at FirebirdSql.Data.FirebirdClient.FbCommand.ExecuteDbDataReader(CommandBehavior behavior) at System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)

We have received following report:

Dynamic SQL Error SQL error code = -104 a string constant is delimited by double quotes

Dynamic SQL Error SQL error code = -104 a string constant is delimited by double quotes

The problem - there is no stack trace.

I have did some research, read forums, stumbled upon those posts: exception with no stack trace - how? and Empty StackTrace. Possible?.

Exception itself is not NULL, as we get text from ex.Message. If the exception was rethrown, even in this case there would be at least one row in stack trace - as of the point where it was rethrown. Similar if the exception originated in another thread. I do not think it has something to do with database system we are using - Firebird. I have few possibilities how empty stack trace might have happened:

• OutOfMemory - program somehow went OOM, thus no stack trace
• Exception at .toString

So far we do not know how to simulate this error, nor have access to EventLogs from machine it originated.

Any corrections to my assumptions? What am I missing? Thanks in advance.