Last Updated: 29 Jul 2019 07:48 by ADMIN

We are evaluating whether to use Telerik to redesign a legacy web app written using an old version of Telerik.

After downloading Trial version on fresh install of windows, I can't add ajax control to form. `I am using visual studio 2019, this is the first version of Telerik installed on this computer.  I just get the "Error Creating Control RadScriptManager1. They do show up in the toolbox so this surprises me.

Very latest version.


Could it be a license issue?

Last Updated: 04 Sep 2019 07:58 by ADMIN
Release R3 2019

The current colors, #0082CC and #FFFFFF that are used for forecolor and backcolor, have 4.14:1 color contrast ratio:

The minimum required color contrast ratio is 4.5:1 for AA Compliance, and 7:1 for AAA Compliance.

A possible alternative color for the #0082CC blue can be #007CC.

Last Updated: 08 Nov 2019 11:26 by ADMIN
Release R1 2020
Created by: Randy
Comments: 1
Category: UI for ASP.NET AJAX
Type: Bug Report

I have a RadCheckboxList In an ASP Panel. When Enabling/Disabling the panel the CheckBoxList does not Enable/Disable.  I tested this with a simple mock up with additional controls that work as expected:


<asp:Panel ID="TestPanel" runat="server" Enabled="true">

<telerik:RadCheckBoxList ID="WeeklyDays" runat="server" Columns="4" AutoPostBack="false">


<telerik:ButtonListItem Text="Monday" Value="2" />

<telerik:ButtonListItem Text="Tuesday" Value="4" />

<telerik:ButtonListItem Text="Wednesday" Value="8" />

<telerik:ButtonListItem Text="Thursday" Value="16" />

<telerik:ButtonListItem Text="Friday" Value="32" />

<telerik:ButtonListItem Text="Saturday" Value="64" />

<telerik:ButtonListItem Text="Sunday" Value="1" Selected="true" />



<telerik:RadTextBox ID="TestText" runat="server"></telerik:RadTextBox>

<telerik:RadDatePicker ID="TestDate" runat="server"></telerik:RadDatePicker>


<br />

<telerik:RadCheckBox ID="ToggleEnabled" runat="server" Text="Toggle Panel" AutoPostBack="true" Checked="true" OnCheckedChanged="ToggleEnabled_CheckedChanged"></telerik:RadCheckBox>



 protected voidToggleEnabled_CheckedChanged(objectsender, EventArgs e)


TestPanel.Enabled = Convert.ToBoolean(ToggleEnabled.Checked);


Last Updated: 14 Aug 2019 12:34 by ADMIN
Created by: Chris Dalessandri
Comments: 3
Category: UI for ASP.NET AJAX
Type: Bug Report

Reproduction steps:

Go to the Telerik demo at
In the Comment box, type "one two".  Do not let the textbox lose focus.
Highlight "two" and start to drag it to move it before "one". The other text ("one") will disappear, and is gone forever, as far as I can tell.

It can be also reproduced with this configuration:

<telerik:RadTextBox RenderMode="Lightweight" runat="server" ID="RadTextBox3" Width="200px" EmptyMessage="Enter comment" TextMode="MultiLine" Height="100px" Resize="None"></telerik:RadTextBox>

Last Updated: 16 May 2019 15:54 by ADMIN
Created by: Sergey
Comments: 1
Category: UI for ASP.NET AJAX
Type: Bug Report


There seems to be a bug with the RadEditor "Find and Replace" feature. I have recorded a screencast available here documenting the issue and will also provide below the information written:

Reproduction Steps:

Expected: '<img' is replaced with '<picture'

Actual:'<img' is replaced with '&lt;picture'

Notes:This seems to be an issue with encoding as &lt; is a less than tag. As you can see in the video, I do not think there is a way to escape the character to allow it to be replaced correctly. If you have additional questions, please ask.


Best Regards

Last Updated: 09 Apr 2019 13:40 by ADMIN
Created by: Anne
Comments: 1
Category: UI for ASP.NET AJAX
Type: Bug Report
Last Updated: 11 Apr 2019 08:13 by ADMIN

I have a problem with the deletecommand of the radgrid control (Telerik.Web.UI 2019.1.215.40).

This happens only in the latest release of Chrome.

I hope you can replicate this issue and eventually fix it. 

Last Updated: 10 Apr 2019 15:26 by ADMIN
When the ribbon bar is set to RibbonBarFloating, RibbonBarPageTop or RibbonBarShowOnFocus the menus cut off so you can't access menu items that would be displayed below bounds of the ribbon bar.

You can see this happening at:

I have also supplied a snip of the issue.
Last Updated: 02 Apr 2019 14:15 by ADMIN
Created by: Scott
Comments: 1
Category: UI for ASP.NET AJAX
Type: Feature Request



Trying to use a web testing tool (Selenium) and using xpath is not always working.  I was wondering if it would be possible to always add an ID property to controls, especially in drop downs etc. so that it can clicked properly.

Last Updated: 27 Mar 2019 21:46 by ADMIN
After the alert was confirmed, a Post Back is expected which does not happen due to a JavaScript exception: Cannot read property 'toString' of null
Last Updated: 10 Apr 2019 15:28 by ADMIN
Bug introduced in build 2019.1.115+ causes 3 extra <p>&nbsp;</p> when user presses Enter key in FireFox.  Happens when Editor is in a Wizard with more than one step.  Bug does not occur in builds prior to 2019.1.115.

Try this to reproduce:

 <telerik:RadWizard runat="server" ID="rwMain" BorderStyle="Solid" BorderColor="LightGray" BorderWidth="1px" RenderMode="Lightweight" DisplayNavigationButtons="True">
            <telerik:RadWizardStep ID="RadWizardStep2" Title="Content Template" StepType="Step">
            <telerik:RadWizardStep ID="RadWizardStep3" Title="Content Editor" StepType="Step">
                <telerik:RadEditor ID="ContentEditor" runat="server" RenderMode="Lightweight"></telerik:RadEditor>
Last Updated: 10 Apr 2019 15:41 by ADMIN

This can be reproduced with the following sample:

<telerik:RadWindow runat="server" ID="RadWindowWithEditor" Height="1000px" OnClientShow="fixEditor"
        <telerik:RadEditor RenderMode="Lightweight" runat="server" ID="RadEditor1" Width="700px" Height="700px">
Lorem ipsum dolor sit amet
<asp:Button ID="Button5" Text="open the RadWindow" runat="server" />
<script type="text/javascript">
    function fixEditor() {
        setTimeout(function () {
            $find("<%=RadEditor1.ClientID %>").onParentNodeChanged();
        }, 100);


Last Updated: 27 Feb 2019 08:52 by Marin
Last Updated: 20 Mar 2019 15:28 by ADMIN
Created by: MailUp Dev
Comments: 5
Category: UI for ASP.NET AJAX
Type: Bug Report
Using Firefox 64.0,  selecting an image doesn't appear the resizing handles which are located on each corner of the object
Last Updated: 20 Dec 2018 14:19 by ADMIN
Created by: Vinson
Comments: 1
Category: UI for ASP.NET AJAX
Type: Bug Report
When I try to replace a white space in RadEditor, it is able to replace the words at the first line. The second one and onwards are not able to replace.


1. Open 'Find And Replace' dialog.

2. Go to 'Replace' tab.

3. Enter a white space for 'Find' text box.

4. Enter any character or word for 'Replace With' text box.

5. Hit on 'Replace All' button.

Reproducible in content which contains table elements and in the live demo:
Last Updated: 11 Feb 2019 10:08 by ADMIN
Created by: Rumen
Comments: 3
Category: UI for ASP.NET AJAX
Type: Bug Report
I'm using couple of Rad Editor controls in my webpart and using ToolProviderID for performance optimization.
I'm initializing one rad editor toolbar from server side and using the same toolbar to provide other rad editors with their toolbar, Bascially I'm using ToolProviderID attribute to initialize other RadEditors, after doing this the Comments and Track Changes feature stop working although their options are selected in the toolbar.

<telerik:RadEditor RenderMode="Lightweight" runat="server" ID="RadEditor1" EnableTrackChanges="true" EnableComments="true">
    <TrackChangesSettings Author="AuthorName" CanAcceptTrackChanges="true" UserCssId="reU0" />
            <telerik:EditorTool Name="AcceptTrackChange" />
            <telerik:EditorTool Name="RejectTrackChange" />
            <telerik:EditorTool Name="AcceptAllTrackChanges" />
            <telerik:EditorTool Name="RejectAllTrackChanges" />
            <telerik:EditorTool Name="EnableTrackChangesOverride" />
<telerik:RadEditor ID="RadEditor2" runat="server" ToolProviderID="RadEditor1" EnableTrackChanges="true" EnableComments="true"></telerik:RadEditor>
<telerik:RadEditor ID="RadEditor3" runat="server" ToolProviderID="RadEditor1" EnableTrackChanges="true" EnableComments="true"></telerik:RadEditor>
Last Updated: 13 Dec 2018 16:38 by ADMIN
Created by: BALA
Comments: 1
Category: UI for ASP.NET AJAX
Type: Feature Request
What is EOL for this version.
UI for ASP.NET AJAX R1 2017 SP1 (version 2017.1.228)
Last Updated: 05 Nov 2018 08:54 by Smit
After having a filter applied, filter value is not cleared when FilterOption was set to "NoFilter".

The following client-side logic would clear the textbox values before the filtering is applied if filter options are set to "NoFilter"

            function onCommand(sender, args) {
                if (args.get_commandName() == "HeaderContextMenuFilter") {
                    var firstTextBox = $("[id$='HCFMRTBFirstCond']")[0].control;
                    var firstFilterOption = args.get_commandArgument().split("|")[1];

                    var secondTextBox = $("[id$='HCFMRTBSecondCond']")[0].control;
                    var secondFilterOption = args.get_commandArgument().split("|")[3];

                    if (firstFilterOption.includes("NoFilter") && firstTextBox.get_value() != "") {
                        var value = firstTextBox.get_value();
                        var newArg = args.get_commandArgument().replace("|" + value + "|?", "||?");
                        args.get_tableView().fireCommand(args.get_commandName(), newArg);

                    if (secondFilterOption.includes("NoFilter") && secondTextBox.get_value() != "") {
                        var value = firstTextBox.get_value();
                        var newArg = args.get_commandArgument().replace("|" + value + "|?", "||?");
                        args.get_tableView().fireCommand(args.get_commandName(), newArg);
Last Updated: 08 Nov 2018 15:00 by ADMIN
The ContextMenu popup is not position properly relative to its target element when the page is horizontally scrolled in Edge. The problem is reproducible with R2 2018.

Steps tp reproduce:
1. Run the code below and scroll the page to the right
2. Right click over a number

<!DOCTYPE html>

<html xmlns="">
<head runat="server">
    <form id="form1" runat="server">
        <telerik:RadScriptManager ID="RadScriptManager1" runat="server">
        <telerik:RadContextMenu ID="rcmMenu" runat="server">
                <telerik:ContextMenuTagNameTarget TagName="a" />
                <telerik:RadMenuItem Text="Menu Item 1" Value="a" />
                <telerik:RadMenuItem Text="Menu Item 2" Value="b" />
        <div style="width: 3500px; height: 100px; position: relative; background-color: yellow;">
            <a style="position: absolute; left: 1000px; top: 40px;" onclick="return showMenu(event);">1000</a>
            <a style="position: absolute; left: 2000px; top: 40px;" onclick="return showMenu(event);">2000</a>
            <a style="position: absolute; left: 3000px; top: 40px;" onclick="return showMenu(event);">3000</a>

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