Dim objZeile As DataRow
        objZeile = tbDataset.Kunden.NewRow()
 
        With objZeile
            .Item("kdnr") = Textkdnr.Text
            .Item("name") = Textname.Text
        End With
 
        tbDataset.Kunden.Rows.Add(objZeile)
        Me.KundenTableAdapter.Update(tbDataset.kunden)
    End Sub

Try
    Me.Validate()
    Me.KundenBindingSource.EndEdit()
    Me.KundenTableAdapter.Update(tbDataset.kunden)
Catch ex As Exception
    MsgBox("Update failed")
End Try