At present, when IE is in Compatibility Mode the UI for ASP.NET AJAX controls use the Classic RenderMode in all cases because of the User Agent string the browser provides.

If RenderMode="Lightweight" and the X-UA-Compatible meta tag with value "IE=edge" is present on the server, the controls will render in the Lightweight mode instead of falling back to Classic.
This will also apply to RenderMode="Auto".

UploadedFiles collection needs to be available across post backs.

Please add support for JQuery 3.x to Telerik ASP.NET for AJAX.  I am able to integrate Telerik into a nice Bootstrap dashboard, but the jquery versions are no compatible.  Telerik is further behind on the jQuery version.

In Chrome and Safari, adding a space with disabled Track Changes right after a tracked text, the space appears inside the <ins> tag instead of outside. 

The issue is reproducible when an   is added in from of the white space, when adding a subsequent white space after a word. The caret is repositioned at the start of the next tag, if such does not exists, it goes to the end of the line.

A workaround is to add the settings in the markup, for example:

<telerik:RadPersistenceManager runat="server" ID="RadPersistenceManager1">
	<PersistenceSettings>
		<telerik:PersistenceSetting ControlID="RadTileList1" />
	</PersistenceSettings>
</telerik:RadPersistenceManager>
<telerik:RadTileList runat="server" ID="RadTileList1">
</telerik:RadTileList>

The disabled items in RadMenu have wrong styles applied and look like enabled.

WORKAROUND:

        .RadMenu .rmGroup a.rmLink.rmDisabled,
        .RadMenu .rmGroup a.rmLink.rmDisabled:hover {
            color: #677277;
        }
        .RadMenu .rmGroup a.rmLink.rmDisabled.rmFocused {
            box-shadow: inset 0 0 3px 1px;
        }




Steps to reproduce:

        <telerik:RadMenu ID="RadMenu1" runat="server" RenderMode="Classic" Skin="Glow">
            <Items>
                <telerik:RadMenuItem Text="Home" NavigateUrl="Default.aspx">
                    <Items>
                        <telerik:RadMenuItem Text="Disabled" Enabled="false"></telerik:RadMenuItem>
                        <telerik:RadMenuItem Text="Home row2"></telerik:RadMenuItem>
                        <telerik:RadMenuItem Text="Home row3"></telerik:RadMenuItem>
                        <telerik:RadMenuItem Text="Home row4"></telerik:RadMenuItem>
                    </Items>
                </telerik:RadMenuItem>
                <telerik:RadMenuItem IsSeparator="true" />
                <telerik:RadMenuItem Text="Grid Page" NavigateUrl="Grid.aspx" />
                <telerik:RadMenuItem IsSeparator="true" />
                <telerik:RadMenuItem Text="About" Enabled="false" />
                <telerik:RadMenuItem IsSeparator="true" />
            </Items>
        </telerik:RadMenu>

When zoom is applied in IE browser and button coordinates are not an integer RadImageButton tries to convert them to an integer on the server on postback and fails.

Workaround:

			<telerik:RadImageButton runat="server" ID="rib1" Width="50" Height="50" OnClick="rib1_Click" Image-Url="~/images/myImage.png"></telerik:RadImageButton>
			<script>
				Telerik.Web.UI.Button.ImageCoordsFunctionality.prototype._calculateCoords = function (e) {
					var container = this._ui.element;
					var pos = $telerik.getLocation(container);
					var scroll = $telerik.getScrollOffset(container, true);

					return new Telerik.Web.UI.Point(parseInt(e.clientX + scroll.x - pos.x), parseInt(e.clientY - pos.y + scroll.y));
				}
			</script>

Steps to reproduce:
1. Open the demo page http://demos.telerik.com/aspnet-ajax/editor/examples/overview/defaultcs.aspx
2. Switch to the 'HTML' mode of the RTE and replace all existing HTML content with the following HTML snippet:
<div>text</div>

3. Switch to the 'Design' mode of the RTE and click once on the 'text' word;
4. Switch keyboard language to Japanese and select 'Hiragana' input type. Place focus on the 'text';
5. Type the 'a' and 'e' characters;

Expected result:
The 'あえ' characters are typed.

Actual result:
Just 'え' character is typed. The 'あ' character is replaced by the 'え'. 

Note:
The first character disappears.
You may need to try several times to reproduce the issue.
The issue is reproducible in Chrome (Version 54.0.2840.99 m).
The issue is not reproducible in Firefox and IE11.

Screencast reproduction: http://screencast.com/t/Lj6plU0di99



Workaround:

<telerik:RadEditor ID="RadEditor1" runat="server">
<Content><p>test</p></Content>
</telerik:RadEditor>

<script>
var editorPrototype = Telerik.Web.UI.RadEditor.prototype;
var onKeyDown = editorPrototype._onKeyDown;
editorPrototype._onKeyDown = function (e) {
if (e.composed) {
   this._pendingTextTypeCmd = {};
}
onKeyDown.call(this, e);
if (e.composed) {
   delete this._pendingTextTypeCmd;
}
};
</script>

RadCombobox with allowed custom text is transperant in Silk in Classic Render mode.

Video: https://www.screencast.com/t/tgubeklglq


Code to reproduce:
        <div style="width: 300px; background-color: red">
            <h2>Allow custom text</h2>
            <telerik:RadComboBox RenderMode="Classic" ID="RadComboBox1" runat="server" Width="100%" AllowCustomText="true" Skin="Silk">
                <Items>
                    <telerik:RadComboBoxItem Text="RadComboBoxItem1" />
                    <telerik:RadComboBoxItem Text="RadComboBoxItem2" />
                    <telerik:RadComboBoxItem Text="RadComboBoxItem3" />
                </Items>
            </telerik:RadComboBox>
        </div>

Additional white border added to the RadRibbonbar buttons in Windows7 skin. The problem is reproducible in Classic rendering.

Steps to reproduce:
1. Open http://demos.telerik.com/aspnet-ajax/ribbonbar/examples/rendermodes/defaultcs.aspx?skin=Windows7

2. Switch to Classic rendering.

Result: All buttons have white border.

The issue can be workarounded by calling preventDefault of the mousedown event when ComboBox item is clicked:
<telerik:RadScriptManager runat="server" />
<script>
	var onDocumentClick = Telerik.Web.UI.RadComboBox.prototype._onDocumentClick;
	Telerik.Web.UI.RadComboBox.prototype._onDocumentClick = function (e) {
		if (!e) e = event;

		var target = e.target || e.srcElement;

		while (target.nodeType !== 9) {
			if (!target.parentNode || target == this.get_element() || target == this.get_dropDownElement()) {
				e.preventDefault();
				return;
			}

			target = target.parentNode;
		}
		onDocumentClick.call(this, e);
	};
</script>

<telerik:RadComboBox ID="RadComboBox1" runat="server" RenderMode="Lightweight" OnClientBlur="OnClientBlur"
	CheckBoxes="true">
	<Items>
		<telerik:RadComboBoxItem Text="Item1" Value="1" />
		<telerik:RadComboBoxItem Text="Item2" Value="2" />
		<telerik:RadComboBoxItem Text="Item3" Value="3" />
		<telerik:RadComboBoxItem Text="Item4" Value="4" />
	</Items>
</telerik:RadComboBox>

<script>
	function OnClientBlur(sender, args) {
		console.log("Blur event");
	}
</script>