Rad Tree & RadCombo Generic Error

[Naveen]

Hi Team,

i am using Radtree and RadCombo(containing Radtree inside) in my project .some times when clicking on radtree or radcombo getting the following errror "message received from the server cannot be parsed".

i am using ajax setting in my project :
<telerik:AjaxSetting AjaxControlID="rdMasterAjaxManager" EventName="rdMasterAjaxManager_AjaxRequest">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="rdcmbTreeview" />
                    <telerik:AjaxUpdatedControl ControlID="Radtree1" />
                </UpdatedControls>
            </telerik:AjaxSetting>
when ever AjaxRequest is firing i am updating both the controls.

please help me.

Regards,
Naveen M