The Bold, Italic, Underline, Subscript and Superscript commands do not work in a combination with EnableTrackChanges="true" and ToolbarMode="RibbonBar".

RadEditor uses a RadWindow for its dialogs so when the global rendering of RadCocntrols on the page is set to Lightweight the dialogs need to be consistent.
There could be implemented a property to control the RenderMode of the dialogs themselves.

When the property 'AutoResizeHeight' is set to 'true' and 'ContentAreaMode' is set to 'Div', the appearance of RadEditor will be distorted in IE10. Also, the height of the editor is reduced the first time HTML view is selected under IE10 and older versions when the same setup is used.

To replicate this (as it is rather difficult to explain) go to http://demos.telerik.com/aspnet-ajax/editor/examples/overview/defaultcs.aspx
Click on the HTML tab and replace all the content with:

<div>
  <div>
    <div style="width: 100%;">foo bar
    </div>
  </div>
</div>

Click back on the Design tab and click at then end of the first line.  When you press enter, the new line will be filled with non breaking spaces equal to the amount the inner-most div was indented.

When creating links in RadEditor if the href attribute has square brackets, opening the hyperlink manager will appear like there is no url at all. 
If OK button is clicked the url disappears.

When the Editor is used in Right to Left mode, the modules at the bottom of the control are not properly positioned and the resizing handler does not point to the right direction - http://screencast.com/t/JwPlpE3zPDzi

The value set to the EmptyMessage of the editor floats outside the EDitor if its length exceeds the Editor's width - http://screencast.com/t/rPLVwFVfU

The error is Sys.InvalidOperationException: Sys.InvalidOperationException: Component 'RadEditor1_dialogOpener' was not found.

When not enabled RadEditor should merely show its content, when Enabled is toggled to true it should render toolbars and add its functionality.

A possible workaround is using the Visible property instead and a div with runat=server as a placeholder for the editor while it is not rendered (its Content property will still return the HTML in it). Thus, the innerHTML server property of the div can be used to set the HTML from RadEditor in it.

RadEditor's height is increasing as the content increases in iPad. The height of the control should remain the same but scrollbars should be displayed in the content area.

When creating a tree view with nodes which on click create instances of the RadEditor and pasting inside the content of the second instance throws a JavaScript error.

The following workaround will help you avoid this behavior:

Set this function to the OnClientLoad property (OnClientLoad = 'OnLoad')

function OnLoad(editor, args) {
var originalGetPasteIFrame = Telerik.Web.UI.Editor.Utils._getPasteIframe;
Telerik.Web.UI.Editor.Utils._getPasteIframe = function (parentDoc, editor) {
if ($telerik.isIE8) {
$telerik.$(this._pasteIframe).remove();
this._pasteIframe = null;
}
return originalGetPasteIFrame.call(this, parentDoc, editor);
}
}

In Q2 2013 the block commands in RadEditor were greatly improved to match desktop editors closely. This means that now block elements like <p> or <div> are required for operations like creating lists, indent/outdent commands.

The default value for the NewLineMode property of the control is BR for historical reasons and thus when the end users press enter they do no longer create elements the block commands can work with. Changing it would be a breaking change, however.
Here is a list with possible implications of changing the default NewLineMode value to P:


Pros:
- The default text editing in modern browsers according to HTML5 specifications (https://dvcs.w3.org/hg/editing/raw-file/tip/editing.html#the-insertparagraph-command) requires that a paragraph is inserted when enter is pressed
- The content generated by the end users by default will integrate better with the improved commands of the control
- Most desktop rich text editing applications (like MS Word) insert a paragraph when enter is pressed


Cons:
- A breaking change in the current control behavior and configuration
- When paragraphs are inserted they will add more margins so the final appearance of the content and the editing process will require more height
- By default, the underlying rich-text editing engine of Firefox uses BR tags and Chrome's - DIV tags


Please use the buttons on the right to vote whether this change should be implemented. If you have anything to add - the comments below can be used.

Similar to the RadComboBox' OnClientFocus event - http://www.telerik.com/help/aspnet-ajax/combobox-onclientfocus.html

When using FormatBlock Tool with text inside <div> element the result differs under the different browsers.

IE:
- cursor placed inside the <div> with no selection: the <div> tag is replaced by the selected heading.
- partially selected text: the <div> is split into two and the selection is wrapped with a heading tag.

FireFox:
- cursor placed inside the <div> with no selection: a heading tag wraps the whole text and the <div> is preserved as parent element.
- partially selected text: the <div> is split into two and the selection is wrapped with a heading tag.

Chrome:
- cursor placed inside the <div> with no selection: the <div> tag is replaced by the selected heading.
- partially selected text: the <div> is split into two and the selection is wrapped with a heading tag.

Steps to reproduce:
1.Type some text in the content of the editor;
2.Press Accept All Track Changes button;
3.Type some other text between two words of the previous text;
4.Press Accept All Track Changes button;

When trying to insert list in a table, the list is inserted outside the td tag.
Switching between Html and Design tag causes the list to be removed from the table.

Under IE the get_text() retrieves only one word if there are many in the cells of a table.

This breaks the result of the RadEditorStatistics tool.

After upgrading to Q2 2003.2.611, I receive this error when an editor is being rendered, whether in a grid as a columntype, or standalone editor. If I remove the column, my popup comes up fine. I've even tried using the latest internal build to no avail.

Error: Unhandled exception at line 3407, column 1 in http://localhost:46674/Telerik.Web.UI.WebResource.axd?_TSM_HiddenField_=ctl00_rsmMaster_TSM&compress=1&_TSM_CombinedScripts_=;;Telerik.Web.UI,+Version=2013.2.709.45,+Culture=neutral,+PublicKeyToken=121fae78165ba3d4:en-US:69657036-201e-4b8d-ba50-faac1961b436:1569bb5f:63b115ed:874f8ea2:dc7e0bd:30f1f089:92fe8ea0:fa31b949:19620875:490a9d4e

0x800a01b6 - JavaScript runtime error: Object doesn't support property or method 'registerControlProperties'