For the time being you can use the following workaround:
<telerik:RadPushButton CssClass="fa bcmbutton" ID="btnAnimate" runat="server" Text="Save & Stay" AutoPostBack="false">
			<Icon PressedCssClass="fa-cog" HoveredCssClass="hovClass" CssClass="rbOk"  />
		</telerik:RadPushButton>

Workaround:

		<script>
			Telerik.Web.UI.Button.IconsUI.prototype.mouseover = function (ev) {
				var that = this,
					iconData = that.options.iconData,
					priIconEl = that.getPrimaryIconElement(),
					secIconEl = that.getSecondaryIconElement(),
					hoveredCssClass = that.options.iconData.primaryHoveredCssClass;

				if (hoveredCssClass) {
					$telerik.$(priIconEl).addClass(hoveredCssClass);
				}

				that._setBackground(priIconEl, iconData.primaryHoveredIconUrl);
				that._setBackground(secIconEl, iconData.secondaryHoveredIconUrl);

				that.base.mouseover(ev);
			},

				Telerik.Web.UI.Button.IconsUI.prototype.mouseout = function (ev) {
					var that = this,
						iconData = that.options.iconData,
						priIconEl = that.getPrimaryIconElement(),
						secIconEl = that.getSecondaryIconElement(),
						hoveredCssClass = that.options.iconData.primaryHoveredCssClass;

					if (hoveredCssClass) {
						$telerik.$(priIconEl).removeClass(hoveredCssClass);
					}

					that._setBackground(priIconEl, iconData.primaryIconUrl);
					that._setBackground(secIconEl, iconData.secondaryIconUrl);

					that.base.mouseout(ev);
				},

				Telerik.Web.UI.Button.IconsUI.prototype.mousedown = function (ev) {
					var that = this,
						iconData = that.options.iconData,
						priIconEl = that.getPrimaryIconElement(),
						secIconEl = that.getSecondaryIconElement(),
						pressedCssClass = that.options.iconData.primaryPressedCssClass;

					if (pressedCssClass) {
						$telerik.$(priIconEl).addClass(pressedCssClass);
					}

					that._setBackground(priIconEl, iconData.primaryPressedIconUrl);
					that._setBackground(secIconEl, iconData.secondaryPressedIconUrl);

					that.base.mousedown(ev);
				},

				Telerik.Web.UI.Button.IconsUI.prototype.mouseup = function (ev) {
					var that = this,
						iconData = that.options.iconData,
						priIconEl = that.getPrimaryIconElement(),
						secIconEl = that.getSecondaryIconElement(),
						isHovered = that.isMouseOverElement(that.element, ev),
						priIconUrl = isHovered && iconData.primaryHoveredIconUrl ? iconData.primaryHoveredIconUrl : iconData.primaryIconUrl,
						secIconUrl = isHovered && iconData.secondaryHoveredIconUrl ? iconData.secondaryHoveredIconUrl : iconData.secondaryIconUrl,
						pressedCssClass = that.options.iconData.primaryPressedCssClass;

					if (pressedCssClass) {
						$telerik.$(priIconEl).removeClass(pressedCssClass);
					}

					that._setBackground(priIconEl, priIconUrl);
					that._setBackground(secIconEl, secIconUrl);

					that.base.mouseup(ev);
				};
		</script>

In case, where paragraph(<p>) with style "font-style: normal" is nested inside table cell (<td>) with style  "style="font-style: italic;" the command incorrectly displays that the content has italic decoration applied and if used the cell is split into three new cells.

Workaround: 

ControlsToSkip="TextArea"


Steps to reproduce:

<telerik:RadFormDecorator RenderMode="Lightweight" runat="server" EnableRoundedCorners="true" DecoratedControls="All" />

    <telerik:RadEditor ID="RadEditor1" runat="server"  RenderMode="Lightweight" AutoResizeHeight="true">
        <Content>
            a<br/>a<br/>a<br/>a<br/>
        </Content>
    </telerik:RadEditor>

1. Set this content to a page
2. Toggle Preview mode

Actual behavior: TextArea remain visible on the page as its styles get overriden
Expected: TextArea is hidden

 

The droppdown tools of RadEditor are not fully visible when ToolbarMode = "RibbonBarFloating" in LightWight.

Reproduction code:
        <telerik:RadEditor ID="reBody" runat="server" ToolbarMode="RibbonBarFloating" RenderMode="Lightweight">
        </telerik:RadEditor>

When you enable the control's keyboard navigation, using the arrow keys for navigation does not work when you use NVDA screen reader.

The encountered issue stems due to inheritance of CSS rules that select globally table elements. 

For the time being you can use the following CSS reset to improve the layout of the Editor's table elements:

.reLayoutWrapper, .reWrapper_corner, .reWrapper_center,
.reLeftVerticalSide, .reRightVerticalSide,
.reTlbVertical, .reToolCell, .reContentCell,
.reToolZone, .reBottomTable, .reEditorModesCell,
.reBottomZone, .reResizeCell {
	border: 0 none !important;
	padding: 0 !important;
}

.Telerik.reWrapper, .Telerik.RadEditor .reContentCell,
.Telerik.reColorPicker, .Telerik.reInsertTable,
.Telerik.reCustomLinks a:hover {
	border: 1px solid #828282 !important;
}

.reLeftVerticalSide, .reRightVerticalSide {
	padding: 1px !important;
}

Note that these CSS rules will affect RadEditor controls outside the RadGrid. If you need to modify only RadEditors inside RadGrid, use CssClass property and change the CSS selectors according the set class name.

Also, upon the used color you may need to change the border-color according to the Skin design.

Resize before focus, and the focus and start typing.
Here is the page:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>

</head>
<body>
    <form id="form1" runat="server">
        <telerik:RadScriptManager ID="RadScriptManager1" runat="server"></telerik:RadScriptManager>

        <telerik:RadTextBox ID="RadTextBox1" runat="server" TextMode="MultiLine" Resize="Vertical"></telerik:RadTextBox>

    </form>
</body>
</html>

http://demos.telerik.com/aspnet-ajax/editor/examples/contentareamodediv/defaultcs.aspx

1. Delete the content
2. Choose AutoResizeHeight from the Configurator

Expected: The contentarea's height equals its wrapper

http://demos.telerik.com/aspnet-ajax/editor/examples/overview/defaultcs.aspx

       1. Insert the following html:
<div style="float: left;">
<img alt="" src="/aspnet-ajax/Editor/images/UserDir/Marketing/Tokyo.png" />
</div>

        2. Click the image and update it via ImageManager

Expected:

<div style="float: left;">
<img alt="" src="/aspnet-ajax/Editor/images/UserDir/Marketing/upload_100.png" />
</div>

Actual: 

<div style="float: left;">
</div>
<img alt="" src="/aspnet-ajax/Editor/images/UserDir/Marketing/upload_100.png" />

RadScheduler Server-side PDF Export does not support Lightweight render mode, as specified in the respective help article:
http://docs.telerik.com/devtools/aspnet-ajax/controls/scheduler/export/pdf/overview.html