The Bold, Italic, Underline, Justify, Indent, Outdent and other commands are not localized in the Undo/Redo dropdowns.

Screenshots:

https://www.screencast.com/t/YLNTiPP7LAk

https://www.screencast.com/t/DS9Y6GrB 


Can be seen at http://demos.telerik.com/aspnet-ajax/editor/examples/localization/defaultcs.aspx. 

OnClientModeChange event is not fired in Mobile RenderMode.

Steps to reproduce:
Run the following code in a mobile Chrome (or mobile emulation) and click the edit Pencil button that switches the edit modes:

        <script type="text/javascript">
            function OnClientModeChange(editor, args) {
                var mode = editor.get_mode();
                switch (mode) {
                    case 1:
                        alert("We are in Design mode");
                        //do something
                        break;
                    case 2:
                        alert("We are in Html mode");
                        //do something
                        break;
                    case 4:
                        alert("We are in Preview mode");
                        //do something
                        break;
                }
            }
        </script>

        <telerik:RadEditor runat="server" OnClientModeChange="OnClientModeChange" ID="RadEditor1" RenderMode="Auto">
        </telerik:RadEditor>

The Delete and Backspace buttons remain enabled in spell check mode, allowing the client to delete selections inside the Editor's content area.

Steps to reproduce:
1. Open http://demos.telerik.com/aspnet-ajax/editor/examples/spellchecker/defaultcs.aspx
2. Click the Spell check icon
3. Select several words from the content and press Backspace/Delete

Result: The selected content is deleted
Expected: The Delete/Backspace button press is ignored

If you type 15 into the font size combo box and click away, a Javascript error is thrown and the font size of the selected cell does not change. If instead you type 16 and click away, the cell changes correctly. 16 is an option in the drop-down but 15 is not.

Error message:

RadSpreadsheetScripts.js:196 Uncaught TypeError: Cannot read property 'get_text' of null


The font size combo box works correctly in the Kendo spreadsheet demo (both with the current and the 2017.1.124 Kendo version ). You can also press enter to commit your typed font size in the Kendo widget, but not in RadSpreadsheet.

Steps to reproduce:
1. Open https://demos.telerik.com/aspnet-ajax/spreadsheet/examples/overview/defaultcs.aspx
2. Click inside the font -size dropdown
3. Type 15 and click outside the SpreadSheet

Result: A JavaScript error is thrown.

In version 2026.1.218.462 the Grid cannot scroll vertically. To work around  it, you can overwrite the built-in function used for scrolling:

<script type="text/javascript">
    Sys.Application.add_init(function () {
        Telerik.Web.UI.GridScrolling.prototype._createTouchScrollExtender = function (toCreate) {
            var contentElement = this._owner.GridDataDiv;

            if (contentElement) {
                var control = this._dropDownTouchScroll;

                if (control) {
                    if (!toCreate) {
                        control.dispose();
                        this._dropDownTouchScroll = null;
                    }
                } else if (toCreate) {
                    this._dropDownTouchScroll = new Telerik.Web.UI.TouchScrollExtender(contentElement);
                    this._dropDownTouchScroll.initialize();

                    if (this.AllowScroll) {
                        contentElement.style.overflow = 'auto';
                    }
                }
            }
        };
    });
</script>

Subresource Integrity is a fairly new security scheme for protecting against malicious script obtained from third-party source (CDNs). It requires that the script tag include a hash of the script content so the browser can verify that it has not been altered.

Telerik controls generate a bunch of script tags for cloudfront.net. It would be swell if the script tags would include the extra attributes necessary to implement subresource integrity. Is this in the roadmap? 

Mozilla provides a security analysis tool which highlights this issue. Look at the results for telerik.com here -> https://observatory.mozilla.org/analyze/www.telerik.com. 

More info available on 
https://infosec.mozilla.org/guidelines/web_security#subresource-integrity
https://www.w3.org/TR/SRI/

Good morning,

we have a strange issue using RadGrid with horizontal scroll and frozen columns: there a resizing of the height which gets user experience not the best.

See attached gif.

Could you please help us?

Please create a method that will convert the old expressions to new format and make them re-usable again.

RadGrid’s SEO Paging activates for normal users in the latest Brave browser, because sessions are misclassified as crawlers (Request.Browser.Crawler evaluates to true).

Even with PagerStyle.EnableSEOPaging set to False, SEO paging still turns on due to crawler detection, and ask whether the legacy Request.Browser.Crawler approach should be removed for ASP.NET WebForms in Telerik.

When EnableSEOPaging is True, query string paging is always used, but when False, the grid still enables SEO paging upon crawler detection, which is being incorrectly triggered in Brave.

If both the CSRF validation and the Session state is turned off, the pages containing AsyncUpload control will throw a null reference exception.

<appSettings>
  <add key="Telerik.AsyncUpload.EnableCsrfValidation" value="false" />
</appSettings>
<system.web>
  <sessionState mode="Off" />

In the demo:
https://demos.telerik.com/aspnet-ajax/editor/examples/trackchanges/defaultcs.aspx

1. (Preparation) Disable TrackChange and Remove all text. Enable Track Change back.

2. Insert table, (HTML View)

3. In the design mode set new paragraph after table:

Insertion of the table dissapeared.

How to fix this issue?

1. Open the demo page linked above.
2. Scroll down to the bottom of the RadListBox using only the mouse wheel.
3. Click on any item (e.g., "USA") to select it.

• The issue does not occur if the user clicks and drags the scrollbar thumb with the left mouse button before selecting an item.
• The issue does not occur if the user clicks the top or bottom navigation arrows on the scrollbar container to scroll.
• The unexpected reset to 0 only triggers when scrolling is performed exclusively via the mouse wheel prior to item selection.

Reproduction - http://somup.com/crVYIDot19

Setup to reproduce:

<telerik:RadContextMenu ID="RadContextMenu1" runat="server">
    <Targets>
        <telerik:ContextMenuDocumentTarget />
    </Targets>
    <Items>
        <telerik:RadMenuItem Text="item">
            <ItemTemplate>
                <asp:TextBox ID="TextBox2" runat="server" />
            </ItemTemplate>
        </telerik:RadMenuItem>
    </Items>
</telerik:RadContextMenu>

<telerik:RadButton runat="server" ID="RadButton2" Text="Postback" AutoPostBack="true" />

Steps to reproduce:

• Show the context menu with a right mouse click on the document.
• Type in a custom value in the TextBox embedded in the menu.
• Perform a postback by clicking on the RadButton.
• Show the context menu again. In the textbox, pick the autocomplete suggestion by the browser.

I'm using a RadTab and one of the RadPageViews starts with an RadAsyncUpload-Control. When I use arrow keys to select this tab and try to use the Tab-Key to focus the next element (the RadAsyncUpload in this case) nothing happens. If any other control (like a textbox) is placed above my upload control there is no problem focusing it.

You can see this in the attached Demoproject when using arrow keys to select to RpvUpload.

After updating to 2026.2 the layout of the SpinButton changed. To work around it, use the below CSS:

html body .RadInput .riUp,
html body .RadInput .riDown {
    height: 50%;
}

verified still present in 2026.2.519 — RadCalendarScript.js

When `EnableNavigationAnimation` is enabled (the default) and the browser zoom is not 100% (and Windows uses fractional display scaling such as 125%/150%),
navigating the RadCalendar to the NEXT month removes the day grid and never renders the new one. The calendar title updates, but the view area stays empty permanently. 
Because `_enableNavigation(false)` and `EnableDateSelect = false` are set before the animation and only restored when it completes, the calendar is also left with navigation 
and date selection disabled — the control is dead until the page is reloaded.

Navigating BACKWARD works correctly (see root cause below for why), which is a useful way to confirm this specific bug.

End users hit this routinely because Chrome persists per-site zoom and many laptops default to 125%/150% display scaling.

 Steps to reproduce:
 1. Page with a default RadCalendar:

<telerik:RadCalendar ID="RadCalendar1" runat="server" EnableNavigationAnimation="true" />

  2. Open in Chrome, set zoom to 110% (Ctrl and +), reload.
  3. Click the "next month" arrow (repeat at a couple of zoom levels, e.g. 110%,
     125%, 150% — whether a given level triggers it depends on rounding of the
     calendar's rendered width).

c = function () {
          o > 0 && r.scrollLeft + r.offsetWidth < r.scrollWidth ||
          o < 0 && r.scrollLeft > 0
              ? (r.scrollLeft += 10 * o, window.setTimeout(c, 10))
              : d();   // d() re-attaches the new table and re-enables the control
      };

`Element.scrollLeft` is a fractional double, while `offsetWidth`/`scrollWidth` are rounded integers. At zoom levels other than 100%, `scrollLeft` clamps at a fractional maximum (e.g. 219.4545) while the rounded widths suggest an integer maximum (e.g. 220 with scrollWidth 440). The forward-direction termination
 check `scrollLeft + offsetWidth < scrollWidth` (439.45 < 440) then remains true forever: `scrollLeft += 10` is clamped and makes no further progress, so the loop reschedules itself indefinitely and `d()` is never called. The new view table is never appended, and navigation/date selection are never re-enabled.

The backward direction terminates on `scrollLeft > 0`, and `scrollLeft` clamps to exactly 0 — which is why only forward navigation is affected.