Load on deman RadCombox in RadGrid Error

[Reza]

I created a usercontrol that contains an enabled load on demand radcombobox.
<div>
<telerik:RadComboBox ShowMoreResultsBox="true" EnableLoadOnDemand="True" EnableVirtualScrolling="true" 
                //set other properties >
                </telerik:RadComboBox>
            </div>

This usercontrol uses to edit data on a radgrid same as your sample.

<telerik:RadGrid //set properties >
            <MasterTableView //set properties >
                <Columns>
                    //My Columns....
                </Columns>
                <EditFormSettings UserControlName="sampleUserControl.ascx" EditFormType="WebUserControl">
                    <EditColumn UniqueName="EditCommandColumn1">
                    </EditColumn>
                </EditFormSettings>
            </MasterTableView>
        </telerik:RadGrid>
when click on combobox on grid, I get "The target xxx$radcombox1' for the callback could not be found or did not implement ICallbackEventHandler."
please help me to solve it.

[Simon]

Hello Reza,

The cause of this error may lie in the code-behind of your page.

Could you paste it here or open a support ticket and send us the page or a small project where the issue can be observed?

In both cases, we will inspect the code and hopefully will determine what is causing the issue.

Thank you in advance.

Greetings,
Simon
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[Anthony]

I have exactly same problem. Reza, could you let me know what did you do to fix this error.

Thanks,

Anthony

[Reza]

I had this problem when i add a control (for example a customvalidator) at position zero in server side code on createchildcontrols method. I added that control on contrstructor to solve it. I hope your problem solve by this way, Because i spent several days to find this problem.

[tparus]

Hi Reza:

Can you share with me what you did to resolve this? I have a page with dynamically created RadDockZone, RadDock and my User Control that contains a load on demand radcombobox. I am getting the same error. Finding a solution is driving me nuts.

Many thanks in advance!