VB.net 2008 ขึ้น error แบบนี้ครับ ไม่รู้จะแก้ยังไงดีครับ

    Private Sub cmdClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdClear.Click
        lsvInstallList.Items.Clear()
        txtNumber.Text = "1"
        txtID_P.Focus()
    End Sub

    Private Sub cmdSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdSave.Click
        If dtpTimeInstall.Value = Today Then
            MessageBox.Show("กรุณาตรวจสอบวันที่ติดตั้งให้ถูกต้องก่อน !!!", "ตรวจสอบวันที่ติดตั้ง", MessageBoxButtons.OK, MessageBoxIcon.Error)
            Exit Sub
        End If

        If txtID_C.Text = "" Then
            MessageBox.Show("กรุณาป้อนรหัสลูกค้า", "ข้อผิดพลาด", MessageBoxButtons.OK, MessageBoxIcon.Error)
            txtID_C.Focus()
            Exit Sub
        End If

        With Conn
            If .State = ConnectionState.Open Then .Close()
            .ConnectionString = strConn
            .Open()
        End With

        Dim sqlInstall As String = ""
        Dim comInstall As OleDbCommand = Conn.CreateCommand()

        With comInstall
            .Connection = Conn
        End With

        sqlInstall = "INSERT INTO t_Install(ID_I,Docno,Type_I,EquipID,EquipName,Model,Color,SerialNumber,"
        sqlInstall &= " Date_I,Date_X,Date_C,Date_F,Period_I,Location_I,Name_C,Engineer,Comment)"
        sqlInstall &= " VALUES('" & LastID_I & "',"
        sqlInstall &= "'" & txtDocno.Text & "',"
        sqlInstall &= "'" & CStr(cboTypeInstall.SelectedValue) & "',"
        sqlInstall &= "'" & txtMainID.Text & "',"
        sqlInstall &= "'" & txtMainName.Text & "',"
        sqlInstall &= "'" & txtMainModel.Text & "',"
        sqlInstall &= "'" & CStr(cboColor.SelectedValue) & "',"
        sqlInstall &= "'" & txtSerialNumber.Text & "',"
        sqlInstall &= "'" & txtRoom.Text & "',"
        sqlInstall &= "'" & txtPeriod.Text & "',"
        sqlInstall &= "'" & dtpTimeInstall.Value = Date.Today & "',"
        sqlInstall &= "'" & dtpExammine.Value = Date.Today & "',"
        sqlInstall &= "'" & dtpCompanyExpire.Value = Date.Today & "',"
        sqlInstall &= "'" & dtpCompanyExpire.Value = Date.Today & "',"
        sqlInstall &= "'" & dtpSupplierExpire.Value = Date.Today & "',"
        sqlInstall &= "'" & txtEngineer.Text & "'"
        sqlInstall &= "'" & txtComment.Text & "'"


        With comInstall
            .CommandType = CommandType.Text
            .CommandText = sqlInstall
            .Connection = Conn
            .ExecuteNonQuery()
        End With

        Dim i As Integer = 0
        Dim sqlInDetail As String = ""

        For i = 0 To lsvInstallList.Items.Count - 1
            sqlInDetail = "INSERT INTO  t_InstallDetail (ID_I,ID_P,Name_P,Model_P,SerialNumber_P,"
            sqlInDetail &= " Number_I,Comment)"
            sqlInDetail &= " VALUES ('" & LastID_I & "',"
            sqlInDetail &= "'" & CStr(lsvInstallList.Items(i).SubItems(0).Text) & "',"
            sqlInDetail &= "'" & CStr(lsvInstallList.Items(i).SubItems(2).Text) & "',"
            sqlInDetail &= "'" & CStr(lsvInstallList.Items(i).SubItems(3).Text) & "',"
            sqlInDetail &= "'" & CStr(lsvInstallList.Items(i).SubItems(4).Text) & "',"
            sqlInDetail &= "'" & CStr(lsvInstallList.Items(i).SubItems(5).Text) & "',"
            sqlInDetail &= "'" & CStr(lsvInstallList.Items(i).SubItems(6).Text) & "',"

            With comInstall
                .CommandType = CommandType.Text
                .CommandText = sqlInDetail
                .Connection = Conn
                .ExecuteNonQuery()
            End With

        Next

        If MessageBox.Show("ท่านต้องการบันทึกข้อมูลการติดตั้งใช่หรือไม่?", "คำยืนยัน", MessageBoxButtons.YesNo, MessageBoxIcon.Information) = DialogResult.Yes Then
            MessageBox.Show("บันทึกรายการติดตั้งเรียบร้อยแล้ว!!!", "ผลการทำงาน", MessageBoxButtons.OK, MessageBoxIcon.Information)

            lsvInstallList.Items.Clear()
            Call ClearCustomerData()
            Call ClearAllInstallData()
            totalNet.Text = "0"
            cmdSave.Enabled = False
            txtDocno.Focus()
        End If

    End Sub