I am experiencing an issue in the Telerik Rad Editor where, after copying and pasting a long sentence in a single line, if I apply bold formatting to a word and place the cursor at the beginning of the bolded word, pressing Enter results in an empty line being inserted between the text. This behavior is reproducible on the Telerik webforms editor demo site as well.

I would appreciate any guidance on how to resolve this issue. Thanks in advance.

Hi,

We are using Material Theme in our application. We see the problem in Rad Editor's Ribbon. Some icons are overlapping the Text. In the demo, it seems to be same behavior.

Regards,
Jamil

When loading RadEditor (Telerik UI for ASP.NET AJAX 2025 Q2) in Internet Explorer 10/11 or Edge in IE Compatibility Mode, the editor does not render and JavaScript errors occur immediately upon page load.

SCRIPT1002: Syntax error
SCRIPT5022: Sys.ArgumentUndefinedException: Value cannot be undefined. Parameter name: type

When we edit the widget > click on the table on a random cell > select Table Properties > The table wizard will always default to the top left cell > This is working as expected.
If you click in the table (not the editor) and select Cell Properties > the wizard will display (highlight) the cell you selected in the table is it expected that when selecting table properties it always default to the left side first box but when selecting cell properties it will show the current cell which we are in.

video link:- https://jam.dev/c/c1cdf56c-53ab-4218-8774-65907b3efd6d 

Table properties > Select cells (e.g the top three) > Border > Select the bottom > 6 PX > Purple > OK > The preview is not showing the changes we want to apply > the preview is showing only the top left cell

video link:- https://jam.dev/c/88c17904-c758-47ab-949c-d29b4775dc6d 

Following  the bug report Cell Properties - Preview only shows top-left cell styling when applying changes to multiple top-row cells > when we navigate the mouse up and down, in the background, we can see only the top left cell with the border we configured. (while initially we selected the top three) > But if now, in the preview page, we will choose the top three > OK >We will see the top three cells showing the design we configured. 

video link:- https://jam.dev/c/ba52bff1-7459-44d6-a647-d3eb5cea07f3. 

From the widget/page > select the middle bottom cell (notice it has no styling) > Table properties > Cell Properties > Select the middle bottom cell again > More Cell Styling > Border > Notice that the top row design is inherited > Is this expected? 

 video link:- https://jam.dev/c/1516e16f-1f7c-4e89-8b19-368edabf5703 

I have observed that when we're in the widget > selecting a cell from the table > clicking on Cell Properties > The top row design is not inherited. 

When using RadEditor with the StripDomEventAttributes content filter enabled, script execution can still occur when switching from HTML to Design mode.

Certain HTML and SVG elements containing attributes such as onload, onclick, or href/to values that start with javascript: are not fully sanitized before the editor’s content is rendered in Design view. As a result, embedded script code can run during the mode transition even though the anti-script filter is active.

Reproduction steps:

Add a RadEditor with the default filters:

<telerik:RadEditor runat="server" ID="RadEditor1"
    ContentFilters="DefaultFilters,StripDomEventAttributes">
</telerik:RadEditor>

1. Load the page.
2. Switch the editor to HTML mode.
3. Paste any of the following samples (look below)
4. Switch to Design view
5. Watch alerts

<svg/onload=alert(1)><svg>
<svg
onload=alert(1)><svg> # newline char
<svg	onload=alert(1)><svg> # tab char
<svgonload=alert(1)><svg> # new page char (0xc)

 

 

 

Steps to Reproduce

1. Open a page containing RadEditor with some content in it
2. In Design mode, select all text (Ctrl+A)
3. Delete the selected text
4. Switch to HTML mode
5. Switch back to Design mode
6. Press Ctrl+Z (Undo) a couple of times.
   

Current Result

• A JavaScript error is thrown in the browser console
• The undo operation fails to restore the deleted content
• Error occurs in _updateBrowserRangeStart method when calling this.range.setStart(e, t)

Expected Result

• The undo operation should work without errors
• The previously deleted text should be restored
• No JavaScript errors should appear in the console

1. In Design mode, select all text (Ctrl + A) and delete it.
2. Switch to HTML mode.
3. Switch back to Design mode.
4. Press Ctrl + Z (Undo).

• The first Ctrl + Z has no effect; the deleted text is restored only after pressing Ctrl + Z a second time.