Last Updated: 21 May 2020 09:41 by ADMIN
Release R2 2020 SP1

When the RenderMode property is set to Lightweight, File manager dialogs still load with Classic render mode, even when the <add key="Telerik.Web.UI.RenderMode" value="Lightweight" /> is set globally in the web.config:


<telerik:radeditor RenderMode="Lightweight" runat="server" id="mainRadEditor" EditModes="Design" >
            <telerik:EditorTool Name="ImageManager"/>
            <telerik:EditorTool Name="DocumentManager"/>


This is causing rendering problems and some of the icons do not load.

Last Updated: 06 May 2020 15:33 by ADMIN
Release R2 2020
Created by: Dan
Comments: 0
Category: Editor
Type: Bug Report

When opening in MS Edge the Table Wizard, the items in Table Layouts tab, Select Table Style dropdown are not populated



As a temporary workaround, you can use the attached script and loaded to the DialogsScriptFile property of the Editor:

<telerik:RadEditor runat="server" DialogsScriptFile="~/dialogscript.js"></telerik:RadEditor>


Last Updated: 05 May 2020 09:34 by ADMIN
Created by: Rohit
Comments: 0
Category: Editor
Type: Bug Report


1. Extract the attached word file.

2. Open it and copy the table content.

3. Go to and paste it without stripping the Word formatting - everything will be fine.

4. Paste it again with stripping the Word formatting - you will see the problem - there is a ticker border around many of the cells:

If you paste the content without stripping the formatting and after that strip it with the FormatStripper the ticker border will not appear.

Last Updated: 22 Apr 2020 07:38 by ADMIN
RadEditor does not offer resx localization for the following Track Changes strings "Inserted by ", "Formatted by ", "Deleted by " as well as for the strings in the Comments dialog: Title, Save, Cancel and Edit.
Last Updated: 06 Apr 2020 07:42 by ADMIN
Created by: prateek
Comments: 1
Category: Editor
Type: Bug Report

Hello Telerik Team,

This is regarding The SpellCheck functionality in the Telerik Editor. Basically whenever a user activates the the SpellCheck from the "abc" button, the page automatically scrolls based on the position of the word. This does not give a good user experience and makes it difficult to work on the page. 

We have seen this issue in the demos you have on your site as well.


To Replicate go to this URL and follow the process below: 

  • Click on the "abc" button at the top left corner of the editor (1 In Image).
  • Notice that the "Suggestion box" scroll the whole page. (2 In Image)
  • Also, if you click on any other word (marked in YELLOW) in the editor, the same issue can be replicated. (3 In Image)

For your reference, we have attached a screenshot of the editor we have in our website.


Let us know if you require any further information to debug it.


Thank you,

Prateek Sanganeria

In Development
Last Updated: 26 Feb 2020 16:10 by ADMIN
Scheduled for R2 2020

ConvertWordLists errors out when pasting bullets in a nested table inside another table from Word. 

Test with the attached word doc in the demo and you'll get the following error:

RadEditor.js:17416 Uncaught TypeError: Cannot read property 'appendChild' of null
    at b.WordListConverter.insertList (RadEditor.js:17416)
    at b.WordListConverter.convert (RadEditor.js:17570)
    at Object.convertWordLists (RadEditor.js:257)
    at Object.cleanPastedContent (RadEditor.js:146)
    at c.RadEditor._onAfterPaste (RadEditor.js:10229)
    at c.RadEditor.afterPasteDelegate (Telerik.Web.UI.WebResource.axd?_TSM_HiddenField_=ctl00_QsfScriptManager_TSM&compress=1&_TSM_CombinedScripts_=%3b%3bSystem.Web.Extensions%2c+Version%3d4.0.0.0%2c+Culture%3dneutral%2c+PublicKeyToken%3d31bf3856ad364e35%3aen-US%3ad28568d3-e53e-4706-928f-3765912b66ca%3aea597d4b%3ab25378d2:6)


Last Updated: 24 Feb 2020 09:42 by ADMIN

We are using CDN and combined scripts as much as possible, and have run into an issue with the RadEditor and applying custom CSS Classes break, e.g. the applied CSS class on the selected content gets stripped for example from 





Last Updated: 19 Feb 2020 12:56 by ADMIN
If you setup multiple RadEditor controls on a single page with RenderMode set to Lightweight then when you change the foreground or background colour on one control, the other controls update their toolbar at the same time.

Sample Page code
    <h1>Editor 1</h1>
    <telerik:RadEditor ID="editor1" runat="server" RenderMode="Lightweight"></telerik:RadEditor>

    <h1>Editor 2</h1>
    <telerik:RadEditor ID="editor2" runat="server" RenderMode="Lightweight"></telerik:RadEditor>

Last Updated: 30 Dec 2019 15:59 by ADMIN

On Google Chrome, the following assingment ends up displaying the body of the html twice within the editor:

radEditor.Content="<HTML><HEAD><STYLE>@import url(./CSS/CI.css);</STYLE></HEAD><BODY><H3>OUTPUT LAYOUT</H3><P>First Name:</P><P>Kerry</P></BODY></HTML>"

The resulting html becomes:
"<html><head><link href="/WebResource.axd?d=IgLlf5SIEZ-4m-Qr1qYVOGbMUL9-osMaMQXxs1c-ODIbmiiieGrgJ2ZuegoRNaCpJJ5zKojqJuk_FD7Cb69kb713UUGq1dCMsrFtihWFgnKkbYnlqQv7Lo2rUoUhmXHopZnTw7Cs3STs4GHdRuMnVHVdYHhRrcdV8Dgdv-U213Y1&amp;t=637050242483188892" type="text/css" id="RADEDITORSTYLESHEET0" rel="stylesheet"></head><body><h3>OUTPUT LAYOUT</h3><p>First Name:</p><p>Kerry</p><h3>OUTPUT LAYOUT</h3><p>First Name:</p><p>Kerry</p></body></html>"

The issue is the "@import url(./CSS/CI.css);" within the Style tag, if the @import url, is removed, then it works as expected.

Works as expected on IE11.

If you add 2 <style> tags, the second one is displayed twice within the editor:

radEditor.Content = "<HTML><HEAD></HEAD><BODY><H3>OUTPUT LAYOUT</H3><P>First Name:</P><P>Kerry</P><style>@import url(\"./CSS/CI.css\");</style><style>@import url(\"./CSS/CI2.css\");</style></BODY></HTML>";
Last Updated: 22 Nov 2019 14:19 by ADMIN
When setting the DialogsCssFile property, the generated markup of the RadEditor wrapper changes from 

Radeditor RadEditor_<MyCustomSkin> reWrapper


Radeditor <MyCustomSkin> reWrapper.

Since the custom skins generated through the Theme Builder requires the Radeditor RadEditor_<MyCustomSkin> reWrapper class syntax, they won't be applied to the RadEditor body.

The string <MyCustomSkin> is the name of the custom skin.

To fix the problem explicitly set the RenderMode property of RadEditor to "Lightweight", i.e.

<telerik:RadEditor RenderMode="Lightweight" DialogsCssFile="~/MyCustomSkin/DialogContents.css" ID="RadEditor1" runat="server" Skin="MyCustomSkin" EnableEmbeddedSkins="false">
            <ImageManager ViewPaths="~/" UploadPaths="~/" />

Last Updated: 05 Nov 2019 17:54 by ADMIN
In RadEditor, when creating a table, then going to the Table Properties/Style builder/Border option, the Border Width information is pushed down and not all options are accessible.
Last Updated: 04 Nov 2019 14:57 by ADMIN
Created by: Chetan
Comments: 1
Category: Editor
Type: Bug Report

Hi Rumen,


I have encountered a problem as follows:

When a table is added to the radeditor with empty cells, after inserting text in  the empty cell and rejecting the track changes, the complete td (cell) is removed.

Figure shows text inserted in empty cell with track changes on

After rejecting this track changes:

The cell has been removed and you can see the space in the end

You can use the following table code to reproduce the same, I have tried this in the demo link:

<table frame="topbot" class="body_table">
            <th class="td_h">Catalyst</th>
            <th class="td_h">Loading [mg cm<sup>&minus;2</sup>]</th>
            <th class="td_h">Tafel slope [mV decade<sup>&minus;1</sup>]</th>
            <th class="td_h">ECSA [cm<sup>2</sup>]</th>
            <th class="td_h"><em>R</em><sub>ct</sub> at &eta; = 100 mV [&Omega;]</th>
            <th class="td_h">&eta; @ <sub>&minus;</sub>10 mA cm<sup>&minus;2</sup><sub>geo</sub> [mV]</th>
            <th class="td_h">&eta; @ &minus;0.2 mA cm<sup>&minus;2</sup><sub>ECSA</sub> [mV]</th>
            <th class="td_h">Current at &eta; = 100 mV [mA cm<sup>&minus;2</sup>]</th>
            <th class="td_h">Mass activity at &eta; = 100 mV [A g<sup>&minus;1</sup>]</th>
            <th class="td_h">TOF<sub>avg</sub> at &eta; = 100 mV (H<sub>2</sub> s<sup>&minus;1</sup>)</th>
            <td class="td1">0.1 C anodized</td>
            <td class="td1">0.081</td>
            <td class="td1">52</td>
            <td class="td1"><ins author="RadEditorUser" command="Insert" timestamp="1572804414617" title="Inserted by RadEditorUser on 11/3/2019, 11:36:54 PM" class="reU0">fdff</ins></td>
            <td class="td1">4.6</td>
            <td class="td1">51</td>
            <td class="td1">74</td>
            <td class="td1">&minus;67.00</td>
            <td class="td1">827.55</td>
            <td class="td1">0.93</td>
            <td class="td1">2.0 C anodized</td>
            <td class="td1">0.172</td>
            <td class="td1">78</td>
            <td class="td1">191.9</td>
            <td class="td1">7.6</td>
            <td class="td1">88</td>
            <td class="td1">122</td>
            <td class="td1">&minus;15.10</td>
            <td class="td1">87.88</td>
            <td class="td1">0.13</td>
            <td class="td1">0.1 C O<sub>2</sub> plasma</td>
            <td class="td1">0.045</td>
            <td class="td1">48</td>
            <td class="td1">5.8</td>
            <td class="td1">3.9</td>
            <td class="td1">78</td>
            <td class="td1">34</td>
            <td class="td1">&minus;24.97</td>
            <td class="td1">559.87</td>
            <td class="td1">6.96</td>
            <td class="td1">2.0 C O<sub>2</sub> plasma</td>
            <td class="td1">0.177</td>
            <td class="td1">84</td>
            <td class="td1">103.4</td>
            <td class="td1">5.0</td>
            <td class="td1">123</td>
            <td class="td1">146</td>
            <td class="td1">&minus;4.65</td>
            <td class="td1">26.25</td>
            <td class="td1">0.072</td>
            <td class="td1">0.1 C heat</td>
            <td class="td1">0.037</td>
            <td class="td1">58</td>
            <td class="td1">7.6</td>
            <td class="td1">94.1</td>
            <td class="td1">163</td>
            <td class="td1">110</td>
            <td class="td1">&minus;0.95</td>
            <td class="td1">25.75</td>
            <td class="td1">0.302</td>
            <td class="td1">2.0 C heat</td>
            <td class="td1">0.630</td>
            <td class="td1">80</td>
            <td class="td1">11.5</td>
            <td class="td1">36.6</td>
            <td class="td1">106</td>
            <td class="td1">65</td>
            <td class="td1">&minus;8.24</td>
            <td class="td1">13.07</td>
            <td class="td1">0.662</td>
            <td class="td1">0.1 C acid</td>
            <td class="td1">0.103</td>
            <td class="td1">70</td>
            <td class="td1">11.1</td>
            <td class="td1">165.2</td>
            <td class="td1">162</td>
            <td class="td1">126</td>
            <td class="td1">&minus;2.09</td>
            <td class="td1"></td>
            <td class="td1">0.199</td>
            <td class="td1">2.0 C acid</td>
            <td class="td1">0.683</td>
            <td class="td1">75</td>
            <td class="td1">22.9</td>
            <td class="td1">14.1</td>
            <td class="td1">102</td>
            <td class="td1">101</td>
            <td class="td1">&minus;9.48</td>
            <td class="td1">13.88</td>
            <td class="td1">1.15</td>

Do let me know if you need any further information on the same.






Last Updated: 02 Oct 2019 14:29 by ADMIN
Test the code below on iPhone and mobile chrome/safari and you'll get a JS error:

<script type="text/javascript">
    EditorCommandList = Telerik.Web.UI.Editor.CommandList;
    EditorCommandList["ApplySizeColor"] = function (commandName, editor, args) {
        if (editor.getSelectionHtml() != "") {
  "FontSize", { value: "4" }); //fire the FontSize command
  "ForeColor", { value: "red" });  //fire the ForeColor command
        else {
            alert("Please, select some text!");
<telerik:RadEditor ID="RadEditor1" runat="server" RenderMode="Auto" NewLineMode="Br" ContentAreaMode="Div" Height="500" Width="100%" Skin="Metro" _OnClientCommandExecuting="OnClientCommandExecuting">
        <telerik:EditorHeaderTool Name="ApplySizeColor" />
        <telerik:EditorHeaderTool Name="Redo" />
        <telerik:EditorHeaderTool Name="MobileEdit" Position="Right" />
        <telerik:EditorHeaderTool Name="ToggleScreenMode" Position="Right" />
                <telerik:EditorTool Name="ApplySizeColor" Text="Apply Size and Color" ShowText="true"></telerik:EditorTool>
Last Updated: 04 Sep 2019 16:00 by ADMIN
The problem appears to be related to the image and table resizing feature (introduced in Q3 2013), implemented for the Chrome browser. When the content has a large amount of nested tables with images, selecting an image is causing a slow operation and even an unexpected crash of the browser. 

With this example code you can disable the feature and resolve the performance issue:

<telerik:RadEditor ID="RadEditor1" runat="server">
<script type="text/javascript">
	Telerik.Web.UI.RadEditor.prototype._initializeResizableWidget =
		function myfunction() { };

Note that this line of code will disable the image/table resizing only for Chrome. Under Firefox and IE this feature is provided by the browser and will still be available.
Last Updated: 04 Sep 2019 15:57 by ADMIN
When you resize the RadEditor beyond the boundaries of the browser's viewport, absolute positioning will be applied to the control, which could result in problems with the layout in certain cases.

You can use the following workaround to fix the positioning of the editor until the problem is resolved. Just add the script below at the end of your page:

<script type="text/javascript">
                var onResizeStart = Telerik.Web.UI.RadEditor.prototype.onResizeStart;
                Telerik.Web.UI.RadEditor.prototype.onResizeStart = function() {
                                var editorWrapper = this.get_element();
                                this.resizeStartPosition = {

                var onResizeEnd = Telerik.Web.UI.RadEditor.prototype.onResizeEnd;
                Telerik.Web.UI.RadEditor.prototype.onResizeEnd = function() {
                                var editorWrapper = this.get_element();
                                if (this.resizeStartPosition && this.resizeStartPosition.position != {                                             
                                                                position: this.resizeStartPosition.position,
                                                                left: this.resizeStartPosition.left
Last Updated: 04 Sep 2019 15:47 by ADMIN
Last Updated: 04 Sep 2019 15:47 by ADMIN
When an Image or a Table elements are being inserted into the content of the editor, the undo command should revert the insertion.
Last Updated: 04 Sep 2019 15:45 by ADMIN
When you copy a table from MS Excel and you paste it in the RadEditor under Chrome, an image that depicts the copied table will be inserted in the content area of the control along with the table.

You can use the following workaround to avoid inserting an image with the table:

        <telerik:RadEditor runat="server" ID="RadEditor1">

        <script type="text/javascript">
            var getImages = Telerik.Web.UI.Editor.ClipboardImagesProvider.prototype.getImages;
            Telerik.Web.UI.Editor.ClipboardImagesProvider.prototype.getImages = function (event) {
                var images =, event);
                if (event.clipboardData && images.length && event.clipboardData.getData("text/html")) {

                    return [];

                return images;
Last Updated: 04 Sep 2019 15:44 by ADMIN
Inserting a table is causing the user to switch to HTML mode and insert manually a br element, so that he could start typing in the next line.

Possible solution is attaching this Client-side method on the OnClientCommandExecuted event of the RadEditor control:

<telerik:RadEditor runat="server" ID="RadEditor1"

<script type="text/javascript">
    function OnClientCommandExecuted(editor, args) {
        var command = args.get_commandName();
        if (command = "InsertTable") {
            var selection = editor.getSelection();
            var range = selection.getRange();
            if (range.pasteHTML) {
                range.pasteHTML("<br />");
            else {

The following workaround entirely changes the behavior by modifying the selection and selects the first TD

<telerik:RadEditor runat="server" ID="RadEditor1" OnClientPasteHtml="OnClientPasteHtml">

<script type="text/javascript">
    var identifierID = "RadEditor_AfterTable";

    function OnClientPasteHtml(editor, args) {
        var commandName = args.get_commandName();

        if (commandName === "InsertTable" || commandName === "TableWizard" ) {
            var currValue = args.get_value();
            currValue = currValue.replace(/<\/table>/gi, "</table><div id=" + identifierID + ">&#x200B;</div>");
            //currValue = currValue + "<div id=" + identifierID + ">&#x200B;</div>";
            setTimeout(function () {
            }, 0);

    function selectFirstTD(editor) {
        var $ = $telerik.$;
        var contBody = editor.get_contentArea();
        var identifier = $(contBody).find("#" + identifierID);
        var table = identifier.prev();
        var elmToSelect = table.find("th")[0] || table.find("td")[0];

        if (elmToSelect.childNodes && !$telerik.isIE) {
            elmToSelect = elmToSelect.childNodes[0].nodeName === "#text" && elmToSelect.childNodes[0];

        var hasNextElement =[0];
        while (hasNextElement && $(hasNextElement).is("style")) {
            hasNextElement = $(hasNextElement).next()[0];

        if (!hasNextElement) {

Last Updated: 04 Sep 2019 15:44 by ADMIN
The main issue is the inconsistent behavior of the borders around the content area.
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