The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).

[Alex Richardson]

Hi guys,

I am trying to upgrade my existing web project where I'm using the RadControls's 2007 Q2 RadAjaxManager to "Prometheus"'s RadAjaxManager.

I have followed instructions in documentation (Adding RadControls 'Prometheus' to an existing application), but I still receive this error when I open a page with "Prometheus" RadAjaxManager:

The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).

What could be wrong?

Regards,
Alex

[Vlad]

Hi Alex,

Please enclose any <script> blocks with server-side expressions with telerik:RadCodeBlock. For example:

<telerik:RadCodeBlock ID="RadCodeBlock1" runat="server">
<script type="text/javascript">
   var myClientID = <%= MyControl.ClientID %>
</script>
</telerik:RadCodeBlock>

Best wishes,
Vlad
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Alex Richardson]

Thanks. I updated the code, and now the error message has changed to:

Collection was modified; enumeration operation may not execute.

[Vlad]

Hi Alex,

Can you post your page declaration if possible? I will try to reproduce this problem locally.

Kind regards,
Vlad
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Alex Richardson]

Of course. This is the declaration (please, let me know if you shall need more, thanks!):

<%@ Page Language="vb" AutoEventWireup="false" MasterPageFile="~/Main.Master" CodeBehind="Poll.aspx.vb" Inherits="MyStudio.Poll" Theme="default"

title="Definitions - Poll" %>

<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="radA" %>

<%@ Register Assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"

Namespace="System.Web.UI" TagPrefix="asp" %>

<%@ Register Assembly="RadGrid.Net2" Namespace="Telerik.WebControls" TagPrefix="radG" %>

<%@ Register Assembly="RadEditor.Net2" Namespace="Telerik.WebControls" TagPrefix="radE" %>

<%@ Register Assembly="RadInput.Net2" Namespace="Telerik.WebControls" TagPrefix="radI" %>

<%@ Register Assembly="RadCalendar.Net2" Namespace="Telerik.WebControls" TagPrefix="radCln" %>

<%@ Register Assembly="RadComboBox.Net2" Namespace="Telerik.WebControls" TagPrefix="radC" %>

<%@ Register Assembly="RadTabStrip.Net2" Namespace="Telerik.WebControls" TagPrefix="radTS" %>

[Vlad]

Hi Alex,

Can you post the aspx of the controls as well?

Greetings,
Vlad
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Alex Richardson]

Sure. Can I send it to you via e-mail?

Regards, Alex

[Konstantin Petkov]

Hello Alex,

Please, submit a support ticket from your Client.NET account and send the problematic application attached there. Please, also add link to this forum thread as reference.

Greetings,
Konstantin Petkov
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Alex Richardson]

OK. Cheers. I will do that.

Regards, Alex!

[William Finnegan]

not sure if you found a workaround, but here's mine:
migrate the script code into your code behind and use the RegisterClientSciptBlock to define the script. RadAjaxManagerProxy isnt happy with the original Java script defined in the ascx/asxp page.

Page.ClientScript.RegisterClientScriptBlock(Me.GetType(), "ClosedUploadPanel", String.Format("function ClosedUploadPanel(){{var oButton = document.getElementById(""{0}"");oButton.click();}}", cmdPopupClosed.ClientID), True)

FYI This is a piece of code to define a serverside callback when closing a radwindow popup.

hope it helps

[Ronaldo]

I'm getting Error 8 Unknown server tag 'telerik:RadCodeBlock'. 

[Vlad]

Hello Ronaldo,

Do you have Telerik.Web.UI.dll in the bin folder of your application?

Sincerely yours,
Vlad
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Ronaldo]

I don't have telerik.web.ui in my bin folder. where can i get it?

[Ronaldo]

hello Vlad,

where can i get telerik.web.ui.dll? why is it not in my bin folder?

[Sebastian]

Hi Ronaldo,

This is the assemly which wraps the source code of our RadControls "Prometheus" controls. You can download them from your Client.net account -> My Licenses -> My Free Trials section.

More about RadControls "Prometheus" you can learn from these online resources on our site:

http://www.telerik.com/products/aspnet-prometheus/what-is-radcontrols-prometheus.aspx

http://www.telerik.com/demos/aspnet/prometheus/Controls/Examples/Default/DefaultCS.aspx

Best,

Stephen
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[yulian_o]

Hello I am receiving the same error even after i removed! all the javascript i had in my control.
Below you can see a code:
there is no chance that direction and/or language + dir will be removed from file if this what causes a problem.

<table cellpadding=0 cellspacing=0 border=0 width=100% dir="<%=langSpecific.getDirection(Session("Lang_Direction"))%>">
<tr class="WhiteSpace"><td align=center>
    <asp:Label ID="lblMessage" runat="server" Text=""></asp:Label>
</td></tr>
<tr><td class="WhiteSpace" align="<%=langSpecific.getAlign(1,Session("Lang_OppositeAlign"))%>">            
    <table cellpadding=0 cellspacing=0 border=0 width=100%>
              <tr><td class="smallSpace"><a name="formTop"></a></td></tr>
              <tr><td width=5></td><td>
               <table cellpadding=0 cellspacing=0 border=0 width=100% dir="<%=langSpecific.getDirection(Session("Lang_Direction"))%>">
                 <tr>
                  <td valign=middle rowspan="2" align="<%=langSpecific.getAlign(0,Session("Lang_Align"))%>">
                    <asp:Image ID="ImgLogo" runat="server" />
                  </td>
                  <td width="5" rowspan="2">&nbsp;</td>
                  <td valign=top width=50%>
                      <table cellpadding=0 cellspacing=0 border=0 dir="<%=langSpecific.getDirection(Session("Lang_Direction"))%>">
                       <tr><td width=5></td><td><asp:Label ID="lblRoundCaption" runat="server" Text="" CssClass="BoldText"></asp:Label>&nbsp;<asp:Label CssClass="BlackText" ID="lblPrintName" runat="server" Text=""></asp:Label></td></tr>                      
                      </table>
                  </td>
                  <td valign=top width=50%>
                      <table cellpadding=0 cellspacing=0 border=0 dir="<%=langSpecific.getDirection(Session("Lang_Direction"))%>">
                      <tr><td width=5></td><td><asp:Label ID="lblCloseDateCaption" runat="server" Text="" CssClass="BoldText"></asp:Label>&nbsp;<asp:Label CssClass="BlackText" ID="lblCloseDate" runat="server" Text=""></asp:Label></td></tr>                     
                    </table>
                  </td>
                </tr>
                <tr><td colspan="2"><asp:Label CssClass="BlackText" ID="lblSwitchModeInfo" runat="server" Text=""></asp:Label></td></tr>
              </table>
           </td><td width=5></td></tr>          
         </table>
       </td></tr>
       <tr><td class="Games_Line"></td></tr>
       <tr><td align="center" class="WhiteSpace">
         <table cellpadding="0" cellspacing="0" border="0" width="100%">
         <tr><td class="Space"></td></tr>      
         <tr>
           <td align="center">
             <table cellpadding="0" cellspacing="0" border="0">
              <tr>
               <td>
                 <radcb:radcombobox ID="mainNumbers" Runat="server"></radcb:radcombobox>
               </td>
              </tr>
             </table>
           </td>
         </tr>
         <tr><td class="Space"></td></tr>      
         </table>
       </td></tr>      
       <tr><td class="WhiteSpace" align="<%=langSpecific.getAlign(1,Session("Lang_OppositeAlign"))%>" width=100%>            
        <table cellpadding=0 cellspacing=0 border=0 width=100% dir="<%=langSpecific.getDirection(Session("Lang_Direction"))%>">                          
          <tr><td class="Games_Line" colspan=2></td></tr>
          <tr><td colspan=2>
           <table cellpadding=0 cellspacing=0 border=0 width=100% dir="<%=langSpecific.getDirection(Session("Lang_Direction"))%>">
           <tr><td width=5></td><td>
           <table cellpadding=0 cellspacing=0 border=0 width=100% dir="<%=langSpecific.getDirection(Session("Lang_Direction"))%>">
             <tr>                                           
          <td width=50% valign=top>
           <table cellpadding=0 cellspacing=0 border=0 width=100%>
            <tr><td colspan=2><asp:Label ID="lblAvailablePrices" runat="server" Text="" CssClass="BoldText"></asp:Label></td></tr>
            <tr><td width=5></td><td>
            <asp:Repeater ID="priceRepeater" DataSourceID="pricesDataSource" runat="server">
            <HeaderTemplate>
             <table cellpadding=0 cellspacing=0 border=0 width=100% dir="<%=langSpecific.getDirection(Session("Lang_Direction"))%>">
              <tr>
                <td align=center><asp:Label ID="lblColumnsNumber" runat="server" Text="" CssClass="BoldText"></asp:Label></td>
                <td align=center><asp:Label ID="lblColumnPrice" runat="server" Text="" CssClass="BoldText"></asp:Label></td>
              </tr>
            </HeaderTemplate>
            <ItemTemplate>
              <tr>
               <td align=center><asp:Label ID="lblPriceType" runat="server" CssClass="BlackText"></asp:Label></td>
               <td align=center><asp:Label ID="lblColumnPrice" runat="server" CssClass="BlackText"></asp:Label></td>
              </tr>             
            </ItemTemplate>
            <FooterTemplate>
              </table>
            </FooterTemplate>
            </asp:Repeater>             
            <asp:SqlDataSource ID="pricesDataSource" runat="server" ConnectionString="<%$ ConnectionStrings:totoConnectionString %>" SelectCommand="Select minColumns,pricePerColumn,requiresMultiple from TTotoColumnPrices Where formType=@typeID">
            <SelectParameters>
              <asp:QueryStringParameter Name="typeID" QueryStringField="typeID" Type="Int32" />            
            </SelectParameters>
            </asp:SqlDataSource>   
            </td>                      
            <tr><td colspan=2><asp:Label ID="lblYourPrice" runat="server" Text="" CssClass="BoldText"></asp:Label>&nbsp;<asp:Label ID="lblCurrPrice" runat="server" Text="" CssClass="BoldText"></asp:Label></td></tr>
           </table>           
          </td>
          <td width=50% valign=middle>
            <table cellpadding=0 cellspacing=0 border=0 width=100% dir="<%=langSpecific.getDirection(Session("Lang_Direction"))%>">             
              <tr>
                <td align=center valign=middle><a href="#"><img src='<%=langSpecific.getImageURL("Clear.jpg", Server.MapPath("."), Session("Lang_Extention"))%>' class="noBorder" /></a></td>
                <td align=center valign=middle><a href="#"><img src='<%=langSpecific.getImageURL("Randomize.jpg", Server.MapPath("."), Session("Lang_Extention"))%>' class="noBorder" /></a></td>
              </tr>
              <tr><td class="Space"></td></tr>
                <asp:HiddenField ID="cycleID" runat="server" />
                <asp:HiddenField ID="ResultValue" runat="server" />
               <tr>
                <td align=center><asp:ImageButton ID="SaveButton" ImageUrl="../Images/Save.jpg" runat="server" /></td>
                <td align=center><asp:ImageButton ID="CheckoutButton" ImageUrl="../Images/Checkout.jpg" runat="server" /></td>
              </tr>
            </table>
          </td>
         </tr>                    
        </table>
        </td>       
        <td width=5></td></tr>       
        </table>
      </td>
    </tr>       
  </table>                
</td></tr>
</table>          

[yulian_o]

Hello
I have tried to make some workaround solution for that issue with Tooltip from prometeus but it gives me the same results.

[Sebastian]

Hi yulian_o,

I assume that you have already tried to use the RadCodeBlock (as my colleague Vlad suggested previously) to wrap the javascript block. If this does not help, consider assembling a stripped working version of your project, demonstrating the issue, and send it enclosed to a formal support ticket. I will examine your complete implementation and will get back to you with more info.
 
Kind regards,
Stephen
the Telerik team

Instantly find answers to your questions at the new Telerik Support Center

[Matthew Erwin]

I ran into this same problem and in trying to follow these threads found myself frustrated that I still couldn't get things working. I finally figured it out after reading about this issue in another thread...what isn't clear is that it isn't just script blocks -- you must wrap ALL blocks of code that contain <% %> inline in the ASPX or ASCX.

See this thread for other comments by the Telerik team: http://www.telerik.com/community/forums/thread/b311D-bcbkeh.aspx

Here is an example of what I had:

    <telerik:RadCodeBlock runat="server">
    <input type="hidden" name="PRN" value="<%=CurrentPRN%>" />
    <input type="hidden" name="PName" value="<%=CurrentPName%>" />
    </telerik:RadCodeBlock>

    <table><tr>
         <td>Name&nbsp;&nbsp;</td>
         <td>
             <telerik:RadCodeBlock runat="server">
             <script type="text/javascript">
                  var PTView = Class.create();
                  PTView.prototype =
                  {
                  //terminated for brevity
                  }
                  PTView.Inside = <%=_varName%>;
             </script>
         </telerik:RadCodeBlock>
         </td>
     </tr>
</table>

[Rajdeep]

Hi,

Even i am facing the same problem.we are trying to update classic radajaxmanager to prometheus (ASPNET Ajax 2008 Q2)

i followed all the instructions and i am receiving this error.

Collection was modified; enumeration operation may not execute.   at System.Web.UI.ControlCollection.ControlCollectionEnumerator.MoveNext()
   at Telerik.WebControls.RadMultiPage.ClearControls()
   at Telerik.WebControls.RadMultiPage.Render(HtmlTextWriter output)
   at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   at System.Web.UI.Control.Render(HtmlTextWriter writer)
   at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   at System.Web.UI.Control.Render(HtmlTextWriter writer)
   at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   at System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer)
   at System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output)
   at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer)
   at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   at System.Web.UI.Page.Render(HtmlTextWriter writer)
   at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   at Telerik.Web.UI.RadAjaxControl.RenderPageInAjaxMode(HtmlTextWriter writer, Control page)
   at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
   at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   at System.Web.UI.Page.Render(HtmlTextWriter writer)
   at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
   at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

WE RUNNING OUT OF TIME ANY HELP VERY MUCH APPRECIATED.

Regards,
Ishwar

[Konstantin Petkov]

Hi Ritz,

I noticed you've posted this in a different thread. We can continue the communication there, thank you.

Regards,
Konstantin Petkov
the Telerik team

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

[Brian Doner]

Hi, I have a control that works fine with classic radControls radAjax, and now am trying to upgrade it to the ASP.NET AJAX version. When I do, I get this error that the controls collection cannot be modified because it contains code blocks. But even if I remove all code blocks (<%=  %>) from the controls and page, I still continue to get the error. This is frustrating, because it worked just fine with the classic radAjax.

[Konstantin Petkov]

Hello Brian,

The ASP.NET AJAX RadAjaxManager operates differently behind the scene compared to the "Classic" RadAjaxManager.

You can send us your markup through a formal support ticket and we will find what is causing the error on your end. We are sorry for the caused inconvenience.

Regards,
Konstantin Petkov
the Telerik team

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

[Robin]

I'm also getting this error message:

master page:

<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Main.Master.cs" Inherits="WebPortalAJAX.WebForms.MainMaster" %>

<!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>
    <title>PAMS Web Portal</title>
    <telerik:RadStyleSheetManager id="StyleSheetManager" runat="server" >
        <StyleSheets>
        </StyleSheets>
    </telerik:RadStyleSheetManager>
    <link href="<%=ResolveUrl("~/Styles/Reset.css")%>" rel="stylesheet" type="text/css" />
    <link href="<%=ResolveUrl("~/Styles/960grid.css")%>" rel="stylesheet" type="text/css" />
    <link href="<%=ResolveUrl("~/Styles/CommonStyles.css")%>" rel="stylesheet" type="text/css" />
    <link rel='shortcut icon' href='<%=ResolveUrl("~/Images/Common/utsLogoU-shortcutIcon.png") %>' />


    <asp:ContentPlaceHolder runat="server" ID="HeadMetaPlaceholder"></asp:ContentPlaceHolder>

    <asp:ContentPlaceHolder runat="server" ID="HeadStylesPlaceholder"></asp:ContentPlaceHolder>

    <asp:ContentPlaceholder runat="server" ID="HeadJavascriptPlaceholder"></asp:ContentPlaceholder>
</head>
<body>
    <form id="form1" runat="server">
        <telerik:RadScriptManager ID="ScriptManager" runat="server">
            <Scripts>
                <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.Core.js" />
                <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.jQuery.js" />
                <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.jQueryInclude.js" />
                <asp:ScriptReference Path="http://code.jquery.com/jquery-git.js" />
            </Scripts>
        </telerik:RadScriptManager>


        <telerik:RadSkinManager ID="SkinManager" Runat="server" Skin="Vista"></telerik:RadSkinManager>




        <header class="fullWidth">
            <section id="TopBar" runat="server">
                <a href="<%=ResolveUrl("~/Default.aspx")%>" title="<%=Resources.Labels.COMMON_PAMS %>">
                    <img src="<%=ResolveUrl("~/Images/Common/utsLogoUnified-Transparent.png")%>" alt="<%=Resources.Labels.UNIFIED_TECHNOLOGY_SOLUTIONS_LOGO %>" />
                </a>

                <div id="topNav">
                    <asp:Panel runat="server" ID="TopNavLoggedIn">
                        <span id="WelcomeMessage" runat="server">Welcome, <br /></span>
                        |
                        <asp:LinkButton runat="server" ID="LogoutButton" ButtonType="LinkButton" OnClick="Logout_Click" />
                    </asp:Panel>
                    <asp:Panel runat="server" ID="TopNavLogedOut">
                        <a id="login" href="<%=ResolveUrl("~/Default.aspx")%>" title="Login" class="topBarLink"><%= Resources.Labels.COMMON_LOGIN%></a>
                    </asp:Panel>
                </div>
            </section>
        </header>


        <asp:Panel ID="MainContainer" runat="server" CssClass="container_12">




            <menu style="position:absolute;top:-32px;right:0px;">
                <telerik:RadMenu ID="SiteMenu" runat="server" dir="rtl"
                                 CollapseAnimation-Duration="300" CollapseAnimation-Type="OutQuart"
                                 ExpandAnimation-Duration="200" ExpandAnimation-Type="OutExpo"
                                 EnableRoundedCorners="true" EnableShadows="true" CssClass="" Skin="Vista" />
            </menu>

            <div>
                <asp:Panel class="SearchPanel" runat="server" ID="SearchPanel">
                    <telerik:RadTextBox runat="server" ID="SearchTextBox"  Width="328"></telerik:RadTextBox>
                    <telerik:RadButton runat="server" ID="SearchButton" OnClick="Search_Click">
                        <Icon PrimaryIconUrl="~/Images/Icons/16/search.png" />
                    </telerik:RadButton>
                </asp:Panel>
            </div>

            <div class="grid_12">
                <div>
                    <asp:ContentPlaceHolder  runat="server" id="PageContent">

                    </asp:ContentPlaceHolder>
                </div>
            </div>

        </asp:Panel>

        <div class="clear"></div>

        <asp:Panel runat="server" ID="Sitemap" class="fullWidth siteMap">
            <div class="clearOverFlowVisible">
                <div id="SiteMapLoggedOut" runat="server">
                    <ul class="marginTopBottom_10">
                        <li><%=Resources.Labels.COMMON_NAVIGATION %></li>
                        <li><a href="<%=ResolveUrl(Resources.Navigation.PAGE_LOGIN) %>" title="<%=Resources.Labels.PAGE_LOGIN_HEADER%>"><%=Resources.Labels.PAGE_LOGIN_HEADER%></a></li>
                    </ul>
                </div>

                <div id="SiteMapLoggedIn" runat="server" />
            </div>
        </asp:Panel>


        <asp:Panel runat="server" id="Footer" class="fullWidth">
            <footer>
                <div class="alignCenter" style="width:200px;">
                    <%=Resources.Labels.POWERED_BY%>
                    <br />
                    <a href="<%=Resources.Navigation.UNIFIED_TECHNOLOGY_SOLUTIONS_COM %>" title="<%=Resources.Labels.POWERED_BY_UNIFIED_TECHNOLOGY_SOLUTIONS_COM %>">
                        <img src="<%=ResolveUrl("~/Images/Common/utsLogo-Transparent.png")%>" alt="<%=Resources.Labels.UNIFIED_TECHNOLOGY_SOLUTIONS_LOGO %>" />
                    </a>
                </div>
            </footer>
        </asp:Panel>

        <asp:ContentPlaceholder runat="server" ID="FooterJavascriptPlaceholder"></asp:ContentPlaceholder>
    </form>
</body>
</html>

Child page:

<%@ Page Title="" Language="C#" MasterPageFile="~/WebForms/Main.Master" AutoEventWireup="true" CodeBehind="PassportManagement.aspx.cs" Inherits="WebPortalAJAX.WebForms.PassportManagement.PassportManagement" %>
<%@ MasterType VirtualPath="~/WebForms/Main.Master" %>



<asp:Content ID="HeadMeta" ContentPlaceHolderID="HeadMetaPlaceholder" runat="server">

</asp:Content>

<asp:Content ID="HeadStyles" ContentPlaceHolderID="HeadStylesPlaceholder" runat="server">

</asp:Content>

<asp:Content ID="HeadJavascript" ContentPlaceHolderID="HeadJavascriptPlaceholder" runat="server">

</asp:Content>

<asp:Content ID="Content1" ContentPlaceHolderID="PageContent" runat="server">
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            <div id="MainContainer" class="container_12">
                <div class="grid_12">
                    <h3><%= Resources.Labels.PAGE_PASSPORT_MANAGEMENT_TITLE%></h3>
                    <span class="subtitle"><%= Resources.Labels.PAGE_PASSPORT_MANAGEMENT_SUB_TITLE%></span>
                    <hr />
                </div>


                <asp:Panel runat="server" ID="PageControls">
                    <div class="grid_12">
                        <asp:ValidationSummary ID="ValidationSummary" runat="server" DisplayMode="BulletList" CssClass="validationMessage" ValidationGroup="PageControls" />
                    </div>

                    <div class="grid_12">
                        <fieldset>
                            <legend><%= Resources.Labels.COMMON_COMPANY %></legend>

                            <div style="margin-bottom:10px;">
                                <telerik:RadAjaxPanel ID="adf" runat="server" LoadingPanelID="loadPanel1">
                                    <telerik:RadComboBox runat="server" ID="CompaniesComboBox" MarkFirstMatch="true" AutoPostBack="true" Width="300" OnSelectedIndexChanged="CompaniesComboBox_SelectedIndexChanged" />
                                </telerik:RadAjaxPanel>
                                <telerik:RadAjaxLoadingPanel ID="loadPanel1" runat="server" />
                                <telerik:RadButton runat="server" ID="AddCompanyButton" OnClick="AddCompanyButton_Click">
                                    <Icon PrimaryIconUrl="~/Images/Icons/commonIcons.png" PrimaryIconCssClass="commonIconsAdd" />
                                </telerik:RadButton>
                            </div>

                            <fieldset style="padding-left:20px;">
                                <legend><%= Resources.Labels.COMMON_PASSPORTS %></legend>


                                <!-- Configurations -->
                                <asp:EntityDataSource ID="PassportsRadGridEntityDataSource" runat="server" OnSelecting="PassportsRadGridEntityDataSource_Selecting"
                                    ConnectionString="name=PAMSDBEntities" DefaultContainerName="PAMSDBEntities" EnableDelete="false" EnableInsert="false"
                                    EntitySetName="Passports" EnableFlattening="False" where="EXISTS(SELECT VALUE cp FROM it.CompanyPassports AS cp WHERE it.PassportId = cp.PassportId AND cp.CompanyId = @CompanyId)"
                                    EntityTypeFilter="Passport">
                                    <WhereParameters>
                                        <asp:Parameter DbType="Int32" Name="CompanyId" />
                                    </WhereParameters>
                                </asp:EntityDataSource>
                                <!-- Configurations -->


                                <telerik:RadGrid ID="PassportsRadGrid" runat="server" DataSourceID="PassportsRadGridEntityDataSource"
                                    AllowPaging="True" AllowSorting="True" AutoGenerateColumns="False"
                                    AutoGenerateDeleteColumn="True" AutoGenerateEditColumn="True"
                                    CellSpacing="0" GridLines="None">

                                    <PagerStyle Mode="NextPrevAndNumeric" />

                                    <MasterTableView DataSourceID="PassportsRadGridEntityDataSource">
                                        <CommandItemSettings ExportToPdfText="Export to PDF" />

                                        <RowIndicatorColumn>
                                            <HeaderStyle Width="20px" />
                                        </RowIndicatorColumn>

                                        <Columns>
                                            <telerik:GridBoundColumn DataField="PassportId" HeaderText="PassportId" UniqueName="PassportId" Visible="False"></telerik:GridBoundColumn>
                                            <telerik:GridBoundColumn DataField="FirstName" HeaderText="First Name" UniqueName="FirstName"></telerik:GridBoundColumn>
                                            <telerik:GridBoundColumn DataField="LastName" HeaderText="Last Name" UniqueName="LastName"></telerik:GridBoundColumn>
                                            <telerik:GridBoundColumn DataField="DepartmentName" HeaderText="Department Name" UniqueName="DepartmentName"></telerik:GridBoundColumn>
                                            <telerik:GridBoundColumn DataField="JobTitle" HeaderText="Job Title" UniqueName="JobTitle"></telerik:GridBoundColumn>
                                            <telerik:GridBoundColumn DataField="CreatedDate" HeaderText="Created Date" UniqueName="CreatedDate"></telerik:GridBoundColumn>
                                            <telerik:GridBoundColumn DataField="LastUpdatedDate" HeaderText="Last Updated Date" UniqueName="LastUpdatedDate"></telerik:GridBoundColumn>
                                            <telerik:GridBoundColumn DataField="ExpiryDate" HeaderText="Expiry Date" UniqueName="ExpiryDate"></telerik:GridBoundColumn>
                                        </Columns>

                                    </MasterTableView>

                                    <HeaderContextMenu CssClass="GridContextMenu GridContextMenu_Default" />
                                </telerik:RadGrid>
                            </fieldset>
                        </fieldset>
                    </div>
                </asp:Panel>


                <asp:Panel runat="server" ID="ErrorMessagePanel" Visible="false">
                    <div class="grid_3"> </div>
                    <div class="grid_6">
                        <div class="box box-error displayBlock" id="ErrorMessageBox" runat="server" onclick="$(this).fadeOut(500)" style="margin: 20px 0;">
                            <img src="<%=ResolveUrl("~/Images/Icons/commonIconPlaceholder.gif") %>" alt="" />
                            <span class="close">x</span><p runat="server" id="ErrorMessageText" style="display: inline;" />
                        </div>
                    </div>
                    <div class="grid_3"> </div>
                </asp:Panel>

                <div class="clear"></div>
            </div>
        </ContentTemplate>
    </asp:UpdatePanel>
</asp:Content>

<asp:Content ID="FooterJavascript" ContentPlaceHolderID="FooterJavascriptPlaceholder" runat="server">

</asp:Content>

[Sebastian]

Hello Robin,

As discussed previously in this thread, try to wrap all server-side code blocks you use in your code inside RadCodeBlocks to see whether this eliminates the exception you get.

Best regards,
Sebastian
the Telerik team