DirectCast - Object not set to an instance of an object???

[flycast]

Additionally, If I serialize a string and then deserialize it it works fine.

Serialize:

        Dim test As String = "Hello"

        ' Persist to file
        Dim save As New SaveFileDialog
        If save.ShowDialog = Windows.Forms.DialogResult.OK Then
            Dim stream As FileStream = File.Create(save.FileName)
            Dim formatter As New BinaryFormatter()
            formatter.Serialize(stream, test)
            stream.Close()
        End If

Deserialize:

        Dim test As String = ""
        If open.ShowDialog = Windows.Forms.DialogResult.OK Then
            Dim fs As FileStream = New FileStream(open.FileName, FileMode.Open)
            Try
                Dim formatter As New BinaryFormatter
                Dim obj As Object = formatter.Deserialize(fs)
                test = CType(obj, String)
            Catch ex As Exception
                MsgBox(ex.Message)
            Finally
                fs.Close()
            End Try
        End If