Workaround:
<telerik:RadTabStrip ID="RadTabStrip1" runat="server" MultiPageID="RadMultiPage1">
	<Tabs>
		<telerik:RadTab Text="tab1" Selected="true"></telerik:RadTab>
		<telerik:RadTab Text="tab2"></telerik:RadTab>
	</Tabs>
</telerik:RadTabStrip>
<telerik:RadMultiPage ID="RadMultiPage1" runat="server">
	<telerik:RadPageView ID="RadPageView1" runat="server" Selected="true">RadPageView 1</telerik:RadPageView>
	<telerik:RadPageView ID="RadPageView2" runat="server">
		<telerik:RadEditor ID="RadEditor1" runat="server" EnableTrackChanges="true"
			TrackChangesSettings-CanAcceptTrackChanges="true" ToolsFile="ToolsTrackChanges.xml">
			<Content>
				<p>paragraph 1</p>
				<p>paragraph 2</p>
			</Content>
		</telerik:RadEditor>

	</telerik:RadPageView>
</telerik:RadMultiPage>

<script type="text/javascript">
	$telerik.$.extend(Telerik.Web.UI.RadEditor.prototype, {
		_initEvents: function() {
			var editor = this;
			if (editor.__original__initEvents) {
				editor.__original__initEvents();
			}
			editor.add_domChange(Function.createDelegate(editor, editor._domChangedHandler));
			editor.attachInternalHandler("keypress", Function.createDelegate(editor, editor._keyPressHandler));
			editor.attachInternalHandler("keydown", Function.createDelegate(editor, editor._keyDownHandlerEnableTrackChangesOverride));
			editor.attachInternalHandler("keydown", Function.createDelegate(editor, editor._keyDownHandler));
		}
	});
</script>

When the EnableTrackCahnges functionality of the Editor is set to true, a context menu is shown only if the user right-clicks over a tracked change. Clicking over a not changed element does not pop-up any context menu (neither the Editor's not the browser one). The issue is reproducible in all browsers.

Steps to reproduce:
1. Run the following configuration:

            <telerik:RadEditor ID="RadEditor1" runat="server" EnableTrackChanges="True">
                <Content>
                    <span>SPAN dssad</span>
                    <div>DIV fsdfksjdfkf</div>
                    <p>Paragraph jfdshfksjdhfksdhk</p>
                </Content>
            </telerik:RadEditor>

2. Right-click over a not track-changed element.

Actual result: No context menu is shown.

Expected result: The Editor's default content menu (or the browser on) is shown.

When a parent control is disabled by setting Enabled to false, all children controls should inherit the behavior and act as disabled. RadEditor does not follow this logic and stays enabled. 

The first div element in the content is stripped out, every time a submit occurs with opened HTML tab.

Instead of null, the String.Empty can be used. 

A possible workaround is to set the import step after all other rules in the CssFile of the RadEditor. CssFile would look like:

.h1
{
    background-color: Aqua;
}
.div
{
    color: Green;
}
@import url(StyleSheet.css);

There some issues when both features are enabled:

    - Add comment to tracked change is impossible;
    - Context menu is broken.

Currently, this command switches from Design to HTML mode and vise versa when EditType="Inline".

In Normal editing mode this tool is disabled in the HTML mode and cannot be used, although it is useful and provides yet another layout option for the default look of the RadEditor.

You can test the additional layout option by running this example:

<telerik:RadEditor runat="server" ID="RadEditor1"
    EditModes="Design" OnClientModeChange="OnClientModeChange">
    <Tools>
        <telerik:EditorToolGroup>
            <telerik:EditorTool Name="Bold" />
            <telerik:EditorTool Name="ToggleEditMode" />
        </telerik:EditorToolGroup>
    </Tools>
</telerik:RadEditor>

<script type="text/javascript">
    function OnClientModeChange(sender, args) {
        setTimeout(function () {
            sender.get_toolAdapter().getToolByName("ToggleEditMode").set_enabled(true);
        },0)
    }
</script>

This tool can be redesigned to be available in the HTML mode in all cases not only when Inline editing mode is enabled.

If some textarea elements are added inside the content area, focusing and typing text inside is almost impossible. There are also cases, where the text overrides the element on typing. 

Additionally, any text input elements are difficult to be selected. It is required to click multiple times so to appear selected.

Using code behind or localization file to change the text of the Design, Preview or HTML buttons break the functionality that enables the end-user to change the modes.

The following snippet can be used as a temporary workaround.

<style type="text/css">
    /* Fixes the visual glitch */
    .reModes a {
        width:auto !important;
    }
</style>

<telerik:RadEditor runat="server" ID="RadEditor1" RenderMode="Lightweight" OnClientLoad="OnClientLoad">
</telerik:RadEditor>

<script type="text/javascript">
    function OnClientLoad(editor, args) {
        var $ = $telerik.$;
         
        if (editor.get_renderMode() != Telerik.Web.UI.RenderMode.Lite) return;

        var designAttr = editor.get_localization()["RadEditorDesignMode".toLowerCase()];
        var htmlAttr = editor.get_localization()["RadEditorHtmlMode".toLowerCase()];
        var previewAttr = editor.get_localization()["RadEditorPreviewMode".toLowerCase()];
        
        $("a[title=\"" + designAttr + "\"]").attr("title", "Design");
        $("a[title=\"" + htmlAttr + "\"]").attr("title", "HTML");
        $("a[title=\"" + previewAttr + "\"]").attr("title", "Preview");
    }
</script>

When a tool has a longer name, part of the text drops to a new line, and causes incorrect layout. 

To resolve you can use the following CSS rule:

.reDropDownBody a.reTool.reToolText {
    white-space: nowrap;
}

Due to this behavior the font name applied is getting cleared when switching to HTML mode.

When pasting list items over an existing one, the list from the clipboard is added to new UL element. The proper behavior it should be to paste the existing content and adapt it to the existing list.

Commonly users add empty anchor elements, e.g, <p><a name="anchor"></a>Some text</p>. By that, they provide a proper anchoring behavior in HTML, and prevent the text from being decorated as link.

The limitation here is that the anchor element cannot be selected, and thus unable to be edited via the LinkManager dialog.

It would be nice, if there is some built-in logic that handles this situation and provide a proper way for the end-users to be able to visually distinguish this anchors and edit them if needed.

You can find attached  a custom solution for such approach.

Using the Hyperlink manager in a RibbonBar toolbar, causes the selection to be lost. By that, adding a hyperlink to an image, the link is inserted to the content, but it does not wrap the image element.

The behavior is different across IE versions. Under IE11, the link seems to disappear.

When two RadEditors with different TrackChanges mode are defined on the page, a JavaScript error is thrown when inserting a list. The issue is reproducible only when the firstly declared RadEditor has EnabledTrackChanges set to false (the default value), while the second one has EnabledTrackChanges set to false.

Temporary workarounds:

Variant 1: Declare the not tracked RadEditors after the tracked ones, so there scripts will be loaded properly.

Variant2: Set the EnabledTrackChanges of all RadEditors on the page to true.



Steps to reproduce
1. Run the following code:

    <telerik:RadEditor ID="RadEditor1" runat="server">
        </telerik:RadEditor>
        <telerik:RadEditor ID="HiddenRadEditor" runat="server" EnableTrackChanges="true">
        </telerik:RadEditor>

2. Write something and press Enter

3. Click on the "Unordered List" tool

Result: A JavaScript error is thrown

If a list with some non-default formatting in the bullet points is pasted, the custom formatting is not applied.

For example, changing the font-size of a bullet point in MS Word list, will be pasted only with relevant formatting in the text node, but will leave the <li> elements stripped out.

It would be nice if there is additional logic to apply the proper formatting in the bullet points accordingly to the one copied from MS Word.