Different Behavior Between DTExecUI And Scheduled Job

I have a very simple SSIS package that reads an environment variable, assigns it to a variable that is sent in an email, and also logs it to a text file. If I execute the package on the server via DTExecUI, it works fine as expected. However, if I schedule it as part of a job, I get the following error:


Code: 0x00000002 Source: Script Task Description: The script threw an exception: Object reference not set to an instance of an object. End Error DTExec: The package execution returned DTSER_FAILURE (1). Started: 9:08:00 AM Finished: 9:08:01 AM Elapsed: 0.859 seconds. The package execution failed. The step failed.

The script is as follows:


Imports System

Imports System.Data

Imports System.IO

Imports Microsoft.SqlServer.Dts.Runtime


Public Class ScriptMain


Public Sub Main()


Dim Path As String = "C:TestEnv.txt"

Dim Env As String = Environment.GetEnvironmentVariable("SSISConfig").ToString()

Dim Sw As StreamWriter


Dts.Variables("SSISConfig").Value = Env


If File.Exists(Path) = False Then


Sw = File.CreateText(Path)

Else


Sw = File.AppendText(Path)

End If

Try


Sw.WriteLine(Env)

Finally


Sw.Close()

End Try





Dts.TaskResult = Dts.Results.Success

End Sub

End Class


I have puttered with this for a while now and can't figure out what the problem is. Any ideas?