Using MVC 4 , Ext.net 4.0
We are in process of upgrading Ext.net 2.0 to 4.0

Getting following parser errors

1) Ext.Net.SeriesCollection must have items of type 'Ext.Net.Series'. 'Tooltip' is of type 'System.Web.UI.HtmlControls.HtmlGenericControl'.

2) Ext.Net.SeriesCollection must have items of type 'Ext.Net.Series'. 'Renderer' is of type 'System.Web.UI.HtmlControls.HtmlGeneriControl'.

3) Ext.Net.SeriesCollection must have items of type 'Ext.Net.Series'. 'Label' is of type 'System.Web.UI.HtmlControls.HtmlGeneriControl'.

Example followed from link : https://examples4.ext.net/#/Chart/Column/Basic/

Code :
   <ext:Panel runat="server" ID="pnlChart" ItemID="pnlChart" Layout="HBoxLayout" Padding="2" Height="335px" Border="false" Region="Center" AutoScroll="true" >
                            <LayoutConfig>
                                <ext:HBoxLayoutConfig Align="Stretch"></ext:HBoxLayoutConfig>
                            </LayoutConfig>
                            <Items>
                                <ext:CartesianChart 
                                    ID="Chart1"
                                    runat="server" EnableTheming="true" 
                                    Shadow="true"
                                    StyleSpec="background:#fff"
                                    Animate="true" Flex="4" Margins="5">
                                    <AnimationConfig Easing="BounceOut" Duration="1000" />
                                    <Store>
                                        <ext:Store ID="storeChart" ItemID="storeChart" runat="server" AutoDataBind="true" Data="<%#ViewBag.dtStoreChart%>">
                                            <Model>
                                                <ext:Model ID="Model1" runat="server">
                                                    <Fields>
                                                        <ext:ModelField Name="id" />
                                                        <ext:ModelField Name="val" />
                                                    </Fields>
                                                </ext:Model>
                                            </Model>
                                        </ext:Store>
                                    </Store>

                                    <Axes>
                                        <ext:NumericAxis
                                            Fields="val"
                                            Grid="true"
                                            Title=""
                                            Minimum="0" AdjustByMajorUnit="true" Maximum="<%#ViewBag.MaxLabelCount%>" AutoDataBind="true">
                                            <Label>
                                                <Renderer Handler="return Ext.util.Format.number(value, '0,0');" />
                                            </Label>
                                        </ext:NumericAxis>

                                        <ext:CategoryAxis
                                            Position="Bottom"
                                            Fields="id"
                                            Title="US Label Count">
                                            <%--<Label>
                                               <Rotate Degrees="270" />
                                           </Label>--%>
                                        </ext:CategoryAxis>
                                    </Axes>

                                    <Series>
                                        <ext:BarSeries
                                            <%--Axis="Left"--%>
                                            Highlight="true"
                                            XField="id"
                                            YField="val">

                                            
                                           <Tooltip ID="Tips1" runat="server" TrackMouse="true" Width="140" Height="28">
                                                <%--<Renderer Handler="this.setTitle(storeItem.get('id') + ': ' + storeItem.get('val'));" />--%>
                                                <Renderer Handler="this.setTitle(storeItem.get('val') + ' ' + (storeItem.get('id').toLowerCase()=='uk spc' ? storeItem.get('id') : (storeItem.get('id')+ ' Labels')));" />
                                           </Tooltip>
                                            <Label
                                                Display="InsideEnd"
                                                Field="val"
                                                Orientation="Horizontal"
                                                Color="#333"
                                                <%--Contrast="true"--%>
                                                >

                                                <Renderer Handler="return Ext.util.Format.number(value, '0');" />
                                            </Label>
                                            <Renderer Fn="barRenderer" />
                                        </ext:BarSeries>
                                    </Series>
                                </ext:CartesianChart>
                                <ext:CartesianChart
                                    runat="server"
                                    Shadow="true" EnableTheming="true" 
                                    StyleSpec="background:#fff"
                                    Animate="true" Flex="4" Margins="5">
                                    <AnimationConfig Easing="BounceOut" Duration="1000" />
                                    <Store>
                                        <ext:Store ID="storeChartUk" ItemID="storeChartUk" runat="server" AutoDataBind="true" Data="<%#ViewBag.dtStoreChartUk%>">
                                            <Model>
                                                <ext:Model runat="server">
                                                    <Fields>
                                                        <ext:ModelField Name="id" />
                                                        <ext:ModelField Name="val" />
                                                        <%--<ext:ModelField Name="archived" />
                                                        <ext:ModelField Name="current" />--%>
                                                    </Fields>
                                                </ext:Model>
                                            </Model>
                                        </ext:Store>
                                    </Store>

                                    <Axes>
                                        <ext:NumericAxis
                                            Fields="val"
                                            Grid="true"
                                            Title=""
                                            Minimum="0" AdjustByMajorUnit="true" Maximum="<%#ViewBag.MaxSPCCount%>" AutoDataBind="true">
                                            <Label>
                                                <Renderer Handler="return Ext.util.Format.number(value, '0,0');" />
                                            </Label>
                                        </ext:NumericAxis>

                                        <ext:CategoryAxis
                                            Position="Bottom"
                                            Fields="id"
                                            Title="UK SPC Count" />
                                    </Axes>
                                    
                                    <%--<Background Fill="rgb(232,246,252)" StandardTheme="Category5" />--%>

                                    <Series>
                                        <ext:BarSeries
                                            <%--Axis="Left" --%>
                                            Stacked="true"
                                            Highlight="true"
                                            XField="id"
                                            YField="val">
                                            <%--<Tooltip ID="Tips3" runat="server" TrackMouse="true" Width="140" Height="28">--%>
                                                <Renderer Handler="this.setTitle(storeItem.get('val') + ' ' + (storeItem.get('id').toLowerCase()=='uk SPC' ? storeItem.get('id') : (storeItem.get('id')+ ' SPCs')));" />
                                                <%--<Renderer Handler="this.setTitle(String(item.value[1] / 1000000) + 'M');" />--%>
                                            <%--</Tooltip>--%>
                                            <Label
                                                Display="InsideEnd"
                                                Field="val"
                                                Orientation="Horizontal"
                                                Color="#333"
                                                <%--Contrast="true"--%>
                                                >
                                                <Renderer Handler="return Ext.util.Format.number(value, '0');" />
                                            </Label>
                                            <Renderer Fn="barRenderer" />
                                        </ext:BarSeries>
                                    </Series>
                                </ext:CartesianChart>
                                <ext:CartesianChart
                                    ID="Chart2"
                                    runat="server"
                                    Shadow="true"
                                    StyleSpec="background:#fff"
                                    Animate="true" Flex="3" Margins="5">
                                    <AnimationConfig Easing="BounceOut" Duration="1000" />
                                    <Store>
                                        <ext:Store ID="storeChart2" ItemID="storeChart2" runat="server" AutoDataBind="true" Data="<%#ViewBag.dtStoreChart2%>">
                                            <Model>
                                                <ext:Model ID="Model2" runat="server">
                                                    <Fields>
                                                        <ext:ModelField Name="id" />
                                                        <ext:ModelField Name="val" />
                                                    </Fields>
                                                </ext:Model>
                                            </Model>
                                        </ext:Store>
                                    </Store>

                                    <%--<Background Fill="rgb(242,250,252)" />--%>

                                    <Axes>
                                        <ext:NumericAxis
                                            Fields="val"
                                            Grid="true"
                                            Title="" AutoDataBind="true"
                                            Minimum="0" Maximum="<%#ViewBag.WeeklyUpdateMax%>" AdjustByMajorUnit="true">
                                            <Label>
                                                <Renderer Handler="return Ext.util.Format.number(value, '0,0');" />
                                            </Label>
                                        </ext:NumericAxis>

                                        <ext:CategoryAxis
                                            Position="Bottom"
                                            Fields="id"
                                            Title="Weekly Stats" />
                                    </Axes>

                                    <Series>
                                        <ext:BarSeries
                                            <%--Axis="Left"--%>
                                            Highlight="true"
                                            XField="id"
                                            YField="val">
                                            <%--<Tooltip ID="Tips2" runat="server" TrackMouse="true" Width="130" Height="40">--%>
                                                <%--<Renderer Handler="this.setTitle(storeItem.get('val') + ' ' + storeItem.get('id') +' Labels <br> Click to view');" />--%>
                                                <%-- +'<br> Click to view details'--%>
                                           <%-- </Tooltip>--%>
                                            <Label
                                                Display="InsideEnd"
                                                Field="val"
                                                Orientation="Horizontal"
                                                Color="#333"
                                               <%-- Contrast="true"--%>
                                                >
                                                <Renderer Handler="return Ext.util.Format.number(value, '0');" />
                                            </Label>
                                            <Listeners>
                                                <ItemClick Handler="welcomeScreen.fillWeeklyStatsGrid(item);"></ItemClick>
                                            </Listeners>
                                            <Renderer Fn="barRenderer" />
                                        </ext:BarSeries>
                                    </Series>
                                </ext:CartesianChart>

                            </Items>
                        </ext:Panel>