RadCombobox not displaying properly after update

[Cesar]

I have updated my telerik dll to 2021 version and I´m facing some problems with radcombobox. I´m not able to open the items and options arrow disappeared.

<telerik:RadComboBox ID="rcbVehicleInfoMake" runat="server" Height="250px" Width="120px" Skin="WindowsXP" EnableLoadOnDemand="True" AllowCustomText="False" ShowMoreResultsBox="True" ItemRequestTimeout="500" HighlightTemplatedItems="True" MarkFirstMatch="True" DropDownWidth="310px" SelectOnTab="True" OffsetX="0" ShowDropDownOnTextboxClick="True" ExternalCallBackPage="../RCBStreamers/VehicleMakes.aspx">
                                                        <HeaderTemplate>
                                                            <table style="width: 300px;">
                                                                <tr>
                                                                    <th style="width: 350px; text-align: left;">
                                                                        Description
                                                                    </th>
                                                                    <th style="width: 50px; text-align: left;">
                                                                        Code
                                                                    </th>
                                                                </tr>
                                                            </table>
                                                        </HeaderTemplate>
                                                        <ItemTemplate>
                                                            <table style="width: 300px; cursor: pointer;">
                                                                <tr>
                                                                    <td style="width: 350px;">
                                                                        <%#DataBinder.Eval(Container, "Attributes['MakeDesc']")%>
                                                                    </td>
                                                                    <td style="width: 50px;">
                                                                        <%#DataBinder.Eval(Container, "Attributes['MakeCode']")%>
                                                                    </td>
                                                                </tr>
                                                            </table>
                                                        </ItemTemplate>
</telerik:RadComboBox>

 

Please let me know if you have any clue about this issue.

[Vessy]

Hello Cesar,

In the latest release the controls come with several render modes and such behavior can be faced if more of one is used on the same page. Can you remove all RenderMode properties from the controls' declarations and see if adding the following lines to the web.config will make a difference?

<appSettings>
    <add key="Telerik.Web.UI.RenderMode" value="classic" />
</appSettings>

You can run the test from the following KB in order to ensure that all render mode on the page are the same:

https://docs.telerik.com/devtools/aspnet-ajax/knowledge-base/common-determine-mixed-render-mode

Regards,
Vessy
Progress Telerik