Script error for some users but not for others

[James O'Brien]

Some users are getting the following script errors when trying to add or edit. But I'm not getting it from the server or running it in Visual Studio 2010. Please see the code below and help.

Error:

Webpage error details

User Agent: 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; MDDR; InfoPath.2; .NET CLR 1.1.4322; .NET4.0C; .NET4.0E; MS-RTC LM 8)

Timestamp: Wed, 10 Nov 2010 15:48:23 UTC

Message: Sys.WebForms.PageRequestManagerServerErrorException: Object reference not set to an instance of an object.

Line: 3

Char: 74672

Code: 0

URI: http://10.137.12.91/Telerik.Web.UI.WebResource.axd?_TSM_HiddenField_=cphAdmin_cphCMS_RadScriptManager1_TSM&compress=1&_TSM_CombinedScripts_=%3b%3bAjaxControlToolkit%2c+Version%3d4.1.40412.0%2c+Culture%3dneutral%2c+PublicKeyToken%3d28f01b0e84b6d53e%3aen-US%3aacfc7575-cdee-46af-964f-5d85d9cdcf92%3aea597d4b%3ab25378d2%3bTelerik.Web.UI%2c+Version%3d2010.2.929.40%2c+Culture%3dneutral%2c+PublicKeyToken%3d121fae78165ba3d4%3aen-US%3a183fb741-216d-4765-9b46-4a1f5d38fdd7%3a16e4e7cd%3aed16cbdc%3a58366029%3ab7778d6c%3af7645509%3a8674cba1%3ac08e9f8a%3aa51ee93e%3a59462f1

<%@ Page Title="NextGen Portal : Home Page Quick Links" Language="C#" MasterPageFile="~/themes/CMS.master" AutoEventWireup="true" CodeFile="HomeQuickLinks.aspx.cs" Inherits="CMS_HomeQuickLinks" %>
<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>
<asp:Content ID="Content1" ContentPlaceHolderID="cphheaderCMS" Runat="Server"></asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="cphCMS" Runat="Server">
    <h1>Home Page Quick Link</h1>
    <telerik:RadAjaxPanel ID="RadAjaxPanel1" runat="server">
    <telerik:RadGrid
        ID="gridQL"
        runat="server"
        AutoGenerateColumns="false"
        OnItemCommand="RadGrid_ItemCommand"
        Height="300"
        OnItemDataBound="RadGrid_ItemDataBound"
        OnRowDrop="grdPendingOrders_RowDrop">
        <MasterTableView DataKeyNames="HomeQuickLinkID">
            <Columns>
                <telerik:GridBoundColumn DataField="HomeQuickLinkID" Display="false"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn DataField="LinkTitle" HeaderText="Link Title"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn DataField="LongShowDate" HeaderText="Show Date"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn DataField="LongUpdatedDate" HeaderText="Last Updated"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn DataField="UpdatedName" HeaderText="Last Updated By"></telerik:GridBoundColumn>
                <telerik:GridButtonColumn ButtonType="LinkButton" Text="Move Up" CommandName="UpQL"><ItemStyle Width="50px"></ItemStyle></telerik:GridButtonColumn>
                <telerik:GridButtonColumn ButtonType="LinkButton" Text="Move Down" CommandName="DownQL"><ItemStyle Width="70px"></ItemStyle></telerik:GridButtonColumn>
                <telerik:GridButtonColumn ButtonType="LinkButton" Text="Edit" CommandName="EditQL"></telerik:GridButtonColumn>
                <telerik:GridButtonColumn ButtonType="LinkButton" Text="Delete" CommandName="DeleteQL"></telerik:GridButtonColumn>
            </Columns>
        </MasterTableView>
        <ClientSettings EnablePostBackOnRowClick="true" AllowRowsDragDrop="false">
            <Selecting AllowRowSelect="True" UseClientSelectColumnOnly="true"/>
        </ClientSettings>
    </telerik:RadGrid>
    <br />
    <asp:HiddenField ID="hideID" runat="server" />
    <table id="entrySettings">
        <tr>
            <td class="label">Title: </td>
            <td>
                <telerik:RadTextBox
                    ID="txtLinkTitle"
                    runat="server"
                    Width="400"
                    MaxLength="400"
                    ValidationGroup="HomeQuickLink"></telerik:RadTextBox>
                <asp:RequiredFieldValidator
                    ID="RequiredLinkTitle"
                    runat="server"
                    ValidationGroup="HomeQuickLink"
                    ControlToValidate="txtLinkTitle"
                    ErrorMessage="Link Title can not be blank!"></asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
            <td class="label">Link: </td>
            <td>
                <telerik:RadTextBox
                    ID="txtLinkURL"
                    runat="server"
                    Width="400"
                    MaxLength="400"></telerik:RadTextBox>
                <asp:RequiredFieldValidator
                    ID="RequiredLinkURL"
                    runat="server"
                    ValidationGroup="HomeQuickLink"
                    ControlToValidate="txtLinkURL"
                    ErrorMessage="Link Title can not be blank!"></asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
            <td class="label" id="FieldLabel">Show Date:</td>
            <td>
                <telerik:RadDatePicker ID="dateShowDate" runat="server"></telerik:RadDatePicker>
                <asp:RequiredFieldValidator
                    ID="RequiredShowDate"
                    runat="server"
                    ErrorMessage="Please enter the show date!"
                    ControlToValidate="dateShowDate"
                    Display="Dynamic"
                    ValidationGroup="HomeQuickLink"></asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
            <td class="label">Created: </td>
            <td><asp:Label
                ID="lblCreated"
                runat="server"></asp:Label>
            </td>
        </tr>
        <tr>
            <td class="label">Updated: </td>
            <td><asp:Label
                ID="lblUpdated"
                runat="server"></asp:Label>
            </td>
        </tr>
    </table>
    <div style="text-align:right">
        <asp:Button
            ID="btnAdd"
            runat="server"
            Text="Add"
            ValidationGroup="HomeQuickLink"
            onclick="btnAdd_Click" />
        <asp:Button
            ID="btnUpdate"
            runat="server"
            Text="Update"
            onclick="btnUpdate_Click"
            ValidationGroup="HomeQuickLink"
            Visible="false" />
        <asp:Button
            ID="btnClear"
            runat="server"
            Text="Clear"
            onclick="btnClear_Click" />
    </div>
    </telerik:RadAjaxPanel>
</asp:Content>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Telerik.Web.UI;

public partial class CMS_HomeQuickLinks : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
            LoadGrid();
    }

    public void LoadGrid()
    {
        gridQL.DataSource = new List<string>(0);
        gridQL.DataBind();
        gridQL.DataSource = NextGen.core.CMS.HomeQuickLinkManager.GetList();
        gridQL.DataBind();
    }

    protected void btnAdd_Click(object sender, EventArgs e)
    {
        NextGen.core.CMS.HomeQuickLink QL = new NextGen.core.CMS.HomeQuickLink();
        NextGen.core.CMS.HomeQuickLinkManager m = new NextGen.core.CMS.HomeQuickLinkManager();
        QL.LinkTitle = txtLinkTitle.Text;
        QL.LinkURL = txtLinkURL.Text;
        QL.ShowDate = (DateTime)dateShowDate.SelectedDate;
        QL.CreatedID = Int32.Parse(Session["ProfileID"].ToString());
        m.Add(QL);
        LoadGrid();
        ClearFields();
    }

    protected void btnUpdate_Click(object sender, EventArgs e)
    {
        NextGen.core.CMS.HomeQuickLink QL = new NextGen.core.CMS.HomeQuickLink();
        NextGen.core.CMS.HomeQuickLinkManager m = new NextGen.core.CMS.HomeQuickLinkManager();
        QL.HomeQuickLinkID = Int32.Parse(hideID.Value);
        QL.LinkTitle = txtLinkTitle.Text;
        QL.LinkURL = txtLinkURL.Text;
        QL.ShowDate = (DateTime)dateShowDate.SelectedDate;
        QL.UpdatedID = Int32.Parse(Session["ProfileID"].ToString());
        m.Edit(QL);
        LoadGrid();
        ClearFields();
    }

    public void ClearFields()
    {
        hideID.Value = "";
        txtLinkTitle.Text = "";
        txtLinkURL.Text = "";
        dateShowDate.Clear();
        lblCreated.Text = "";
        lblUpdated.Text = "";
        LoadGrid();
        btnAdd.Visible = true;
        btnUpdate.Visible = false;
    }

    protected void RadGrid_ItemCommand(object source, GridCommandEventArgs e)
    {
        ClearFields();
        int QLID = (int)e.Item.OwnerTableView.DataKeyValues[e.Item.ItemIndex]["HomeQuickLinkID"];
        if (e.CommandName == "RowClick" || e.CommandName == "EditQL")
            GetQL4Edit(QLID);

        if (e.CommandName == "DeleteQL")
        {
            NextGen.core.CMS.HomeQuickLinkManager m = new NextGen.core.CMS.HomeQuickLinkManager();
            m.Remove(QLID);
            ClearFields();
        }

        if (e.CommandName == "UpQL")
        {
            NextGen.core.CMS.HomeQuickLinkManager m = new NextGen.core.CMS.HomeQuickLinkManager();
            m.OrderUp(QLID);
            LoadGrid();
        }

        if (e.CommandName == "DownQL")
        {
            NextGen.core.CMS.HomeQuickLinkManager m = new NextGen.core.CMS.HomeQuickLinkManager();
            m.OrderDown(QLID);
            LoadGrid();
        }
    }

    protected void RadGrid_ItemDataBound(object sender, Telerik.Web.UI.GridItemEventArgs e)
    {
        //if (e.Item is GridDataItem)
        //{
        //    foreach (GridDataItem item in gridAnnouncements.MasterTableView.Items)
        //    {
        //        if (item.ItemIndex == 0)
        //        {
        //            LinkButton btn = (LinkButton)item["UpAnnouncement"].Controls[0];
        //            btn.Visible = false;
        //            item.Display = false;
        //            break; //terminates the for loop
        //        }
        //    }
        //}
    }

    public void GetQL4Edit(int intID)
    {
        NextGen.core.CMS.HomeQuickLink QL = NextGen.core.CMS.HomeQuickLinkManager.GetRecord(intID);
        hideID.Value = intID.ToString();
        txtLinkTitle.Text = QL.LinkTitle;
        txtLinkURL.Text = QL.LinkURL;
        dateShowDate.SelectedDate = QL.ShowDate;
        lblCreated.Text = QL.CreatedName + " on " + QL.CreatedDate.ToShortDateString() + " " + QL.CreatedDate.ToShortTimeString();
        lblUpdated.Text = QL.UpdatedName + " on " + QL.UpdatedDate.ToShortDateString() + " " + QL.UpdatedDate.ToShortTimeString();
        btnAdd.Visible = false;
        btnUpdate.Visible = true;
    }

    protected void btnClear_Click(object sender, EventArgs e)
    {
        ClearFields();
    }

    protected void grdPendingOrders_RowDrop(object sender, GridDragDropEventArgs e)
    {
        //int o = 0;
        //NextGen.core.CMS.HomeQuickLinkManager m = new NextGen.core.CMS.HomeQuickLinkManager();
        //foreach (GridDataItem i in e.[ReorderedItemsLists])
        //{
        //    o = o + 1;
        //    m.EditOrder((int)draggedItem.GetDataKeyValue("HomeQuickLinkID"), o);
        //}
        //LoadGrid();
    }
}

[Tsvetoslav]

Hi James,

You should take into consideration the difference between Advanced databinding and Simple databinding for the RadGrid control and rework your code along the lines of the former. Whenever you need to populate the grid with new data, assign its DataSource property and call its Rebind() (not DataBind() ) method.

Hope this information helps.

Regards,
Tsvetoslav
the Telerik team

[James O'Brien]

You believe my binding is what's creating this error? I so this all through my application and never had a problem. The error is pointing to The Ajax Script Manager?

[Maria Ilieva]

Hi James O'Brien,

Please review the answer provided in the firstly opened support ticket. I hope it will help.
If further questions arise please consider continuing the correspondence in the support ticket for easier tracking.

Regards,
Maria Ilieva
the Telerik team

[Craig Wallace]

I am getting the same error after upgrading to 2010.3.1215.40.  Can you share the solution?

Craig

[Maria Ilieva]

Hi Craig,

Thank you for contacting us.

The mentioned error mostly appears if the same part of the page is updated with the both RadAjaxManager and RadAjaxPanel at the same time. Please note that using both ajax controls (RadAjaxManager and RadAjaxPanel for updating the same content on the page is not supported scenario. Adding RadAjaxPanel into the RadAjaxManager settings may lead to a lot of different issue.
I hope this helps.



Best wishes,
Maria Ilieva
the Telerik team

[Craig Wallace]

Hi Maria,

It seems I had upgraded to the trial version of the assemblies, which caused the problem.

Craig