[vb.net] Index was out of range

[Langella]

Salve ragazzi ho il seguente errore, mi potete aiutare?

Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

Questo il codice:

Private Sub DtGrid_CellContentClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DtGrid.CellContentClick


        If e.ColumnIndex = 0 Then
            MessageBox.Show("Hai cliccato sul pulsante apri")
            Dim nomefile As String = DtGrid.SelectedRows.Item(5).ToString
            'apri il process per il file


            Process.Start("acrord32.exe")


        End If


        Try
            PopolaCampi()


        Catch ex As Exception
            Exit Sub
        End Try
    End Sub