Combobox Load on demand problems

[Matt]

I am trying to get the combobox to load on demand and be searchable but am having problems.  I have followed the demos but can get it to work.
Here is what I have.

Aspx page:

<telerik:RadComboBox ID="RadComboBox1" runat="server" AutoPostBack="True" CollapseDelay="0"
                            ExpandDelay="0" Filter="StartsWith" ItemsPerRequest="10"
                            MarkFirstMatch="true" EnableAutomaticLoadOnDemand="True" EmptyMessage="-New Menu-"
                            ShowMoreResultsBox="True" EnableItemCaching="false" EnableLoadOnDemand="True" EnableVirtualScrolling="True">
                            <HeaderTemplate>
                                <table style="width: 275px" cellspacing="0" cellpadding="0">
                                    <tr>
                                        <td style="width: 175px; height: 13px">Name
                                        </td>
                                        <td style="width: 60px; height: 13px">ID
                                        </td>
                                        <td style="width: 40px; height: 13px">Grade
                                        </td>
                                    </tr>
                                </table>
                            </HeaderTemplate>
                            <ItemTemplate>
                                <table style="width: 275px" cellspacing="0" cellpadding="0">
                                    <tr>
                                        <td style="width: 175px;">
                                            <%# DataBinder.Eval(Container.DataItem, "FullName")%>
                                        </td>
                                        <td style="width: 60px;">
                                            <%# DataBinder.Eval(Container.DataItem, "StudentID")%>
                                        </td>
                                        <td style="width: 40px;">
                                            <%# DataBinder.Eval(Container.DataItem, "DisplayGrade")%>
                                        </td>
                                    </tr>
                                </table>
                            </ItemTemplate>
                        </telerik:RadComboBox>

C# to bind

RadComboBox1.DataTextField = "FullName";
    RadComboBox1.DataValueField = "StudentID";
    RadComboBox1.DataSource = dt_students;
    RadComboBox1.DataBind();

I get this error when I click on it.
"There was an error in the callback.s[]_$$__$$__$$_False_$$_"

Any help would be great thank you.
Matt

[Matt]

Can someone help we are trying to decide if we are going to buy this software.
Matt

[Nencho]

Hello Matt,

I noticed that you had submitted 2 similar tickets. Therefor, I would like to ask you to continue our conversation in the other ticket (Ticket ID - 681636), in order to keep the correspondence consistent.

All the best,
Nencho
the Telerik team

[Salim]

I have a similar issue, is there any resolution ?

[Mary]

I am getting this error on the latest version 

If ajax is enabled and any other ajax event has occurred entering text in the combo box this error is dipslayed

There was an error in the callback.s[]_$$__$$__$$_False_$$_

[Nencho]

Hello Mary,

Do you use the RadComboBox in some UserControl, nested in your page? If so, please make sure that if it is dynamically added on your page, it should be recreated on each Page_load. This is needed, because the ComboBox' LOD feature triggers callbacks, and if the control is not added at each Page_Load, it won't be able ti find its callbacks owners.

However, if this is not the case, please demonstrate us the implementation that you have at your end.

Regards,
Nencho
Telerik by Progress

[Mary]

I am using the combo box in a user control but this code has been working for a number of years.  I reverted to the previous telerik version and it is still occurring

[Nencho]

Hello Merry,

Could you please submit a support ticket, along with am sample example attached, where the experienced issue replicates. The LOD mechanism which works upon callbacks should be the same as when he was initially implemented. This is why, having the issue occurred once the version was updated is quite strange.

I am looking forward to your reply.

Regards,
Nencho
Telerik by Progress