Throws an exception: an element with the same key already exists in the dictionary

[Robert]

Hi everybody,
Using two controls RadRotator and RadMenu on the one and the same page we've met the following problem: from time to time an exception is thrown. We are using Telerik RadControls for ASP.NET Ajax controls version 2009.2.826.35. The stack trace and technical information are below:

Source:
mscorlib

StackTrace:
в System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) в System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) в Telerik.Web.UI.Common.ControlRenderer.GetUrl(Control controlRef, String resourceName) в Telerik.Web.UI.Common.ControlRenderer.GetControlScripts(Control controlRef) в Telerik.Web.UI.RadDataBoundControl.RenderScriptsNoScriptManager(HtmlTextWriter writer) в Telerik.Web.UI.RadDataBoundControl.Render(HtmlTextWriter writer) в System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer) в System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) в System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) в System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer) в System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer) в System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer) в System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) в System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) в System.Web.UI.Control.Render(HtmlTextWriter writer) в System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer) в ASP.main_master.__RendermainForm(HtmlTextWriter __w, Control parameterContainer) в System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) в System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) в System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) в System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) в System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) в System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) в System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) в System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) в System.Web.UI.Control.Render(HtmlTextWriter writer) в System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer) в System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) в System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) в System.Web.UI.Page.Render(HtmlTextWriter writer) в System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) в System.Web.UI.Control.RenderControl(HtmlTextWriter writer) в System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

TargetSite:
ThrowArgumentException

InnerExceptionMessage:
null

RequestInfo:
UserAgent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0)
UserLanguages: ru-RU

Will appreciate any help.
Thanks.

[Pero]

Hello Robert,

I tested the following code and everything seems to be working fine. Could you please provide a sample project where we can observe and debug the issue?
.aspx

<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <asp:ScriptManager ID="ScriptManager1" runat="server">
        <Scripts>
            <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.Core.js" />
        </Scripts>
    </asp:ScriptManager>
    <div>
        <asp:Button ID="Button1" runat="server" Text="Postback" />
    </div>
    <telerik:RadMenu ID="Menu1" runat="server">
        <Items>
            <telerik:RadMenuItem Text="Item 1">
                <Items>
                    <telerik:RadMenuItem Text="Item 2">
                    </telerik:RadMenuItem>
                    <telerik:RadMenuItem Text="Item 3">
                    </telerik:RadMenuItem>
                    <telerik:RadMenuItem Text="Item 4">
                    </telerik:RadMenuItem>
                </Items>
            </telerik:RadMenuItem>
            <telerik:RadMenuItem Text="Item 2">
                <Items>
                    <telerik:RadMenuItem Text="Item 2">
                    </telerik:RadMenuItem>
                    <telerik:RadMenuItem Text="Item 3">
                    </telerik:RadMenuItem>
                    <telerik:RadMenuItem Text="Item 4">
                    </telerik:RadMenuItem>
                </Items>
            </telerik:RadMenuItem>
            <telerik:RadMenuItem Text="Item 3">
                <Items>
                    <telerik:RadMenuItem Text="Item 2">
                    </telerik:RadMenuItem>
                    <telerik:RadMenuItem Text="Item 3">
                    </telerik:RadMenuItem>
                    <telerik:RadMenuItem Text="Item 4">
                    </telerik:RadMenuItem>
                </Items>
            </telerik:RadMenuItem>
            <telerik:RadMenuItem Text="Item 4">
                <Items>
                    <telerik:RadMenuItem Text="Item 2">
                    </telerik:RadMenuItem>
                    <telerik:RadMenuItem Text="Item 3">
                    </telerik:RadMenuItem>
                    <telerik:RadMenuItem Text="Item 4">
                    </telerik:RadMenuItem>
                </Items>
            </telerik:RadMenuItem>
        </Items>
    </telerik:RadMenu>
    <telerik:RadRotator ID="Image_Rotator" runat="server" CssClass="image_rotator" Width="100"
        Height="100" ScrollDirection="Up" ScrollDuration="1000" RotatorType="AutomaticAdvance"
        FrameDuration="1000" PauseOnMouseOver="false" ItemWidth="100" ItemHeight="100">
        <ItemTemplate>
            <div style="border: 1px solid red; width: 100%; height: 100%;">
                <span>
                    <%#Container.DataItem.ToString()%></span>
            </div>
        </ItemTemplate>
    </telerik:RadRotator>
    </form>
</body>
</html>

.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;

public partial class Default_Rotator : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Image_Rotator.DataSource = new string[] { "Item 0", "Item 1", "Item 2", "Item 3", "Item 4", "Item 0", "Item 5", "Item 6", "Item 7", "Item 8" };
        Image_Rotator.DataBind();
    }
}

Sincerely yours,
Pero
the Telerik team