"The size of the uploaded file exceeds max size allowed" is thrown even if the file is under the specified maximum upload file size.

The error is reproducible in the Default demo -> http://demos.telerik.com/aspnet-ajax/editor/examples/overview/defaultcs.aspx.

Open the Document manager and upload some unsupported file which size does not exceed 200 kb. For example upload a small image file. You'll get the following error:

The size of the uploaded file exceeds max size allowed.
The extension of the uploaded file is not valid. Please, provide a valid file!

while only this line should be shown: The extension of the uploaded file is not valid. Please, provide a valid file!

RadCalendar and RadDatePicker cannot pass the following check by https://achecker.ca/checker/index.php

WCAG 2.0 guideline
Section

1.3 Adaptable: Create content that can be presented in different ways (for example simpler layout) without losing information or structure.
Success Criteria 1.3.1 Info and Relationships (A) 

Check 245: Data table with more than one row/column of headers does not use id and headers attributes to identify cells.

Repair: Add id and headers attributes to table cells so they identify the cells that relate to the headers.

Error Line 597, Column 8:
<table id="ctl00_ContentPlaceholder1_RadDatePicker1_calendar_Top" class="rcMainTable" summary="Table …

Steps to reproduce

Go to https://achecker.ca/checker/index.php

Paste https://demos.telerik.com/aspnet-ajax/datepicker/accessibilityandinternationalization/wcag2.0andsection508accessibility/defaultcs.aspx
or 
https://demos.telerik.com/aspnet-ajax/calendar/accessibility-and-internationalization/wcag-2.0-and-section-508-accessibility/defaultcs.aspx

See the results -> 

Check 245: Data table with more than one row/column of headers does not use id and headers attributes to identify cells.
Repair: Add id and headers attributes to table cells so they identify the cells that relate to the headers.
Error Line 568, Column 8:
<table id="ctl00_ContentPlaceholder1_RadDatePicker1_calendar_Top" class="rcMainTable" summary="Table ...


=======================================

WORKAROUND:

$telerik.$("table.rcMainTable tbody th").each(function (idx, el) {
    var thId = $telerik.$(el).attr("id");
    $telerik.$(el).siblings("td").attr("header", thId);
})

http://screencast.com/t/CySy2iAoiG4n

The print preview resulted by the Splitter's print() method appears blank in Chrome in case there are CSS files passed as an argument to method.

Steps to reproduce:
1. Open http://demos.telerik.com/aspnet-ajax/splitter/examples/printpane/defaultcs.aspx in Chrome
2. Click in the "Print LeftPane" button


Result: An empty print-preview window is shown.

There are some issues with the appearance of the gauges in RTL mode. They vary across browsers.

An easy fix is to add a CSS class to each of them and force direction: ltr:

<telerik:RadRadialGauge CssClass="rtlFix" ID="radialGauge1" runat="server" Width="272px" Height="272px">
    . . . . .
</telerik:RadRadialGauge>

.rtlFix
{
    direction: ltr;
}

If you need to swap the places of the min and max value the Reverse property of the Scale inner tag must be set to true.

It becomes hard to see the checked checkboxes because of the selected color it has by default matches the select color of the grid

Solution:

        .RadGrid_BlackMetroTouch .rgSelectedRow .RadCheckBox.RadButton_BlackMetroTouch .rbToggleCheckboxChecked::before,
        .RadGrid_Bootstrap .rgSelectedRow .RadCheckBox.RadButton_Bootstrap .rbToggleCheckboxChecked::before,
        .RadGrid_Metro .rgSelectedRow .RadCheckBox.RadButton_Metro .rbToggleCheckboxChecked::before,
        .RadGrid_MetroTouch .rgSelectedRow .RadCheckBox.RadButton_MetroTouch .rbToggleCheckboxChecked::before {
            color: white;
        }

        .RadGrid_Glow .rgSelectedRow .RadCheckBox.RadButton_Glow .rbToggleCheckboxChecked::before,
        .RadGrid_Office2010Black .rgSelectedRow .RadCheckBox.RadButton_Office2010Black .rbToggleCheckboxChecked::before,
        .RadGrid_Telerik .rgSelectedRow .RadCheckBox.RadButton_Telerik .rbToggleCheckboxChecked::before,
        .RadGrid_WebBlue .rgSelectedRow .RadCheckBox.RadButton_WebBlue .rbToggleCheckboxChecked::before {
            color: black;
        }

Sample to reproduce the behavior and compare the default colors in other states/cases:

        <telerik:RadCheckBox runat="server" ID="rcb1"></telerik:RadCheckBox>
        <br />
        <telerik:RadCheckBox runat="server" ID="rcb2" Checked="true"></telerik:RadCheckBox>
        <telerik:RadSkinManager runat="server" ID="RadSkinManager1" Skin="Bootstrap" ShowChooser="true">
        </telerik:RadSkinManager>
        <telerik:RadFormDecorator ID="RadFormDecorator1" runat="server" DecoratedControls="All" RenderMode="Lightweight" />
        <asp:CheckBox ID="Checkbox1" Text="some checkbox" runat="server" />
        <telerik:RadGrid ID="RadGrid1" runat="server" OnNeedDataSource="RadGrid1_NeedDataSource" RenderMode="Lightweight">
            <MasterTableView>
                <Columns>
                    <telerik:GridClientSelectColumn></telerik:GridClientSelectColumn>
                    <telerik:GridTemplateColumn HeaderText="rad check box column">
                        <ItemTemplate>
                            <telerik:RadCheckBox runat="server" ID="RadCheckBox1"></telerik:RadCheckBox>
                            <br />
                            <telerik:RadCheckBox runat="server" ID="RadCheckBox2" Checked="true"></telerik:RadCheckBox>
                        </ItemTemplate>
                    </telerik:GridTemplateColumn>
                </Columns>
            </MasterTableView>
            <ClientSettings>
                <Selecting AllowRowSelect="true" />
            </ClientSettings>
        </telerik:RadGrid>

And a dummy data source that is not a good data source in general, but it will suffice to get this running so one can observe

    protected void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
    {
        (sender as RadGrid).DataSource = "abcdef";
    }

When you open a RadNotification in a scrolled page in Edge, it will appear higher than expected or it might not appear at all depending on how much the page is scrolled. 

You can avoid the issue by placing the following script at the end of your page:

		<script type="text/javascript">
			Telerik.Web.UI.RadNotification.prototype._originalSetPopupValue = Telerik.Web.UI.RadNotification.prototype._setPopupVisible;
			Telerik.Web.UI.RadNotification.prototype._setPopupVisible = function(x, y) 
			{
				if (Telerik.Web.Browser.edge) {
					var offsetY = window.pageYOffset;
					var offsetX = window.pageXOffset;

					if (document.documentElement.scrollTop == 0 && document.body.scrollTop > 0)
						y += offsetY;
					if (document.documentElement.scrollLeft == 0 && document.body.scrollLeft > 0)
						x += offsetX;
				}
				this._originalSetPopupValue(x, y);
			}
		</script>

The CloudUpload's Progressbar is not initially shown when uploading files  in MS Edge v. 40.15063 (Creator's Edition)

File drag and drop is broken in MS Edge Creator's Edition. Reproducible in the following demo:

http://demos.telerik.com/aspnet-ajax/asyncupload/examples/draganddrop/defaultcs.aspx

When AJAX is enabled for the Grid with the <PagerStyle Mode="Advanced"> or <PagerStyle Mode="NextPrevNumericAndAdvanced"> the Go To Page by Number and Change Page Size Bugtons would not work.

On the other hand, if changing the Page or PageSize by typing and hitting the ENTER key instead of clicking the buttons, the Grid will behave accordingly.

Issue appears in RenderMode="Lightweight"

RadGrid base styles override skins e.g. "border: 1px solid" will override any value for "border-color" that come from non-embed skins.

Pressing ENTER over a list item not only creates a new li, but also inserts additional <br> element.

Video: https://www.screencast.com/t/PZcYTKEtY4v

Steps to reproduce:
1. Open in Chrome:
2. Switch to Html mode and insert the following content:
<ol>
    <li>123 456
    <ol>
        <li>abc</li>
    </ol>
    </li>
    <li>789</li>
</ol>

3. Switch to design mode
4. Put the cursor inside the first li (e.g. before 5) and press ENTER

Result: A <br> element is added in the beginning of the new <li> element

  <telerik:RadSlider ID="RadSlider_Ticks" runat="server" MinimumValue="0" MaximumValue="5"
                                        SmallChange="1" LargeChange="1" ItemType="tick" Height="40px" Width="400px" TrackPosition="TopLeft"
                                        AnimationDuration="400" ThumbsInteractionMode="Free" AutoPostBack="True"
                                         Skin="Metro"      RenderMode="Classic"  >
                                    </telerik:RadSlider>