When I set RadWindow property VisibleTitlebar="false" then top border is missing on window.
Here is sample code:
<telerik:RadWindow runat="server" ID="GenerateReportWaitWindow" Width="440px" Height="200px" 
                    VisibleTitlebar="false" Modal="true" ReloadOnShow="false" VisibleStatusbar="false" 
                    VisibleOnPageLoad="false" EnableShadow="false" Animation="Fade" Behaviors="None"
                    Title="Čakajte prosím...">
                    <ContentTemplate>
                        <div style="min-height: 66%;">
                            <div style="padding-top: 30px; padding-bottom: 45px; text-align: center; font-weight: bold;">
                                <asp:Label ID="Label4" runat="server">Prebieha vytváranie tlačovej zostavy. Čakajte prosím.</asp:Label>
                              
                                <asp:Label ID="Label5" runat="server">(V závislosti od počtu záznamov to môže trvať aj niekoľko minút...)</asp:Label>
                                <asp:Label ID="Label6" runat="server" ForeColor="Red" Style="display: none;"></asp:Label>
                          
                            </div>
                            <div style="margin-left: auto; margin-right: auto; text-align: center;">
                                <asp:Image ID="Image2" runat="server" ImageUrl="~/Images/Animated/loading1.gif" />
                            </div>
                        </div>
                    </ContentTemplate>
                </telerik:RadWindow>

Admin comment:
Actually there is 1px top border, but it is hard to be noticed. As a temporary solution, one can increase it via the following padding:

Copy Code
<style>
    .RadWindow {
        padding: 4px 5px 5px !important;
    }
</style>

In lightweight the issue is not observed:

<telerik:RadRibbonBar runat="server" RenderMode="Classic">
    <Tabs>
        <telerik:RibbonBarTab Text="home">
            <%-- duplicate the group and items inside to replicate more easily --%>
            <telerik:RibbonBarGroup Text="Documents">
                <Items>
                    <telerik:RibbonBarButton Text="Item 1" />
                </Items>
            </telerik:RibbonBarGroup>
        </telerik:RibbonBarTab>
    </Tabs>
</telerik:RadRibbonBar>

Workarounds:
- Use the Lightweight render mode of the FormDecorator;
- Use RadCheckBox instead of asp:CheckBox;
- Use the following styles:
.rfdRadioChecked::before, .rfdRadioUnchecked::before,
.rfdCheckboxChecked::before, .rfdCheckboxUnchecked::before {
    content: none !important;
}

A workaround is to remove the loading sign functionality by placing the following script at the end of the form tag

The second override is necessary only if you use the OnClientDataLoaded event to alter the data and add fields in the data object that do not exist in the server response. You need to rename the OnClientDataLoaded method call to use your actual method name.

You can find an example of both workarounds and their usage attached.

Some additional information:
- If possible, move the tiles out of the AJAX request, as this will eliminate all of the problems. Depending on the actual scenario perhaps you can make sure they are not in an update panel (e.g., position them absolutely on the page while keeping their markup out of the partial postback).
- consider moving any data formatting logic from the event handler to the template. You can define functions that format the code in the template, not only in the event. An example is available in the attached file. Alternatively, you can return the data formatted from the web service.
- consider reducing the time interval for the requests, because after the AJAX request, only 1 of 2 requests will update the tile UI.

There are missing methods in the TypeScript definitions provided. 

You can find attached a file that illustrates what needs to be updated.

1. Click the ComboBox

2. Select an item in its dropdown

3. Expected: no exception on selection, actual: A "Selection out of range" exception is thrown.

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Telerik.Web.UI;

public partial class ComboBoxNavigation : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            
        }
    }

    private DataTable CreateTestTable()
    {
        DataTable table = new DataTable();
        table.Columns.Add("Text");
        table.Columns.Add("Value");
        table.Columns.Add("test");
        table.Rows.Add("Item1", "1", "aaa");
        table.Rows.Add("Item1", "1", "aaa");
        table.Rows.Add("Item1", "1", "aaa");
      
        return table;
    }

    protected void rcbStaff_ItemsRequested(object sender, RadComboBoxItemsRequestedEventArgs e)
    {

        RadComboBox rcbUser = sender as RadComboBox;
        rcbUser.DataSource = CreateTestTable();
        rcbUser.DataTextField = "Text";
        rcbUser.DataValueField = "Value";
        rcbUser.DataBind();

    }

    protected void rcbStaff_SelectedIndexChanged(object sender, RadComboBoxSelectedIndexChangedEventArgs e)
    {

    }
}

            <telerik:RadNavigation ID="RadNavigation1" runat="server">
                <Nodes>
                    <telerik:NavigationNode Text="Home"  />
                    <telerik:NavigationNode Text="Candidate"  />
                    <telerik:NavigationNode Text="Preliminary Candidate"  />
                    <telerik:NavigationNode Text="StaffSearch" CssClass="staffSearchWrapper rootTemplate">
                        <NodeTemplate>
                            <telerik:RadComboBox ID="rcbStaff" 
                                AutoPostBack="true" 
                                runat="server"
                                EnableLoadOnDemand="True" 
                                OnItemsRequested="rcbStaff_ItemsRequested"
                                OnSelectedIndexChanged="rcbStaff_SelectedIndexChanged"
                               >
                            </telerik:RadComboBox>
                        </NodeTemplate>
                    </telerik:NavigationNode>
                </Nodes>
            </telerik:RadNavigation>

The current page FileList items are not properly updated when the paging is enabled. Returning to a previously paged folder is properly restored to page 1, but it keeps showing the content of lastly listed page. The issue is reproducible in all explorer modes of the control.

Video - http://screencast.com/t/KVpgADxanuh

Scenario description and workaround follow. Note the comments in the workaround and test before using, because it introduces some other unwanted behaviors, mostly related to the bottom/right edge of the zone.
       
WORKAROUND 1:

     <div id="zone" style="width: 600px; height: 500px; background: yellow;"></div>
            <telerik:RadWindow runat="server" ID="rw1" RenderMode="Lightweight" VisibleOnPageLoad="true" Left="0" Top="0" RestrictionZoneID="zone"></telerik:RadWindow>
            <script>
                Telerik.Web.UI.Window.LightweightView.prototype._resizingHandler = function(resizable, args){
                    $telerik.cancelRawEvent(args.get_domEvent());

                    var edges = this.restrictBounds,
                        bounds = this._getResizeBounds(args),
                        borders = this.resizeHelper.borders,
                        fullBounds = {
                            x: bounds.x - borders.left,//originally, subtract
                            y: bounds.y - borders.top,//originally, subtract
                            width: bounds.width + borders.horizontal,
                            height: bounds.height + borders.vertical};
                    //debugger
                    //console.log(fullBounds);
                    //changing the direction in which borders are counted above (+ or -) changes the behavior and the potential issues
                    //if you subtract from the position, resizing will not be available next to the top/left border of the restriction zone
                    //if you add to the position, resizing will be available but the user can resize in the direction of the zone bounds and thus, out of the bounds of the zone, so dragging may become unavailable
                    //also, this will make resizing worse when the window touches the right or bottom of the zone
                    var inContainer = this.window._checkRestrictionZoneBounds(edges, fullBounds);
                    
                    bounds.width = Math.max(resizable.options.constraints.minWidth, bounds.width);
                    bounds.height = Math.max(resizable.options.constraints.minHeight, bounds.height);

                    args.set_cancel(true);
                    if(inContainer && this.touchCount++ > 0)
                    {
                        var style = this.ui.container.style;
                        style.left = bounds.x + "px";
                        style.top = bounds.y + "px";
                        this._setWidth(bounds.width);
                        this._setHeight(bounds.height);

                        this._currentResizeBounds = bounds;
                    }
                }
            </script>

WORKAROUND 2:
Add this to the resizeEnd and dragEnd events of the RadWindow to try and have it never touch the sides of the restriction zone at all.

				function keepThisWindowInBounds(sender) {
					if (!sender.isMinimized() && !sender.isMaximized()) {
						var position = sender.getWindowBounds();
						var rzRect = document.getElementById(sender._restrictionZoneID).getBoundingClientRect();
						// note rzRect height and width are both 1px bigger than the rzElement clientWidth and clientHeight
						// check width and height
						if (position.width > rzRect.width - 3) {
							position.width = rzRect.width - 3;
							sender.set_width(position.width);
						}
						if (position.height > rzRect.height - 3) {
							position.height = rzRect.height - 3;
							sender.set_height(position.height);
						}
						var needToMove = false;
						if (position.x < 1) {
							needToMove = true;
							position.x = 1;
						} else if (position.x > rzRect.width - position.width - 2) {
							needToMove = true;
							position.x = rzRect.width - position.width - 2;
						}
						if (position.y < 1) {
							needToMove = true;
							position.y = 1;
						} else if (position.y > rzRect.height - position.height - 2) {
							needToMove = true;
							position.y = rzRect.height - position.height - 2;
						}
						if (needToMove)
							sender.moveTo(position.x, position.y);
					}
				}

When using:

Value = "(null)"
Text = "(no user)"

as item in the ListBox, the filter must work correctly, and after opening the menu the item should be checked if previously filtered.

Additionally if the item have NULL value instead of "(null)" The visible value must be localized. 

The Table Wizard dialog, the Table Properties tab shows Cell Padding and Cell Spacing fields, but this fields can only apply values. If you edit them through the HTML mode or the Properties Inspector module, the fields in Table Properties dialog will not be updated.

There is a bug in the editor when using the image manager to insert an image after creating a new image.  This is recreated on the live demo site - http://demos.telerik.com/aspnet-ajax/editor/examples/overview/defaultcs.aspx

1. Open the image manager in the editor.
2. Click on an image editor after selecting an image.
3. Use the resizing tool to resize and save a new version of the image. 
4. Once the save is made, both images (the original and the newly created) are selected and when you click insert, both images will be inserted.

The manually entered value of RadDateTimePicker is replaced with the original one in Batch Edid mode in iPad.

To reproduce this incorrect behavior add a new 

<telerik:GridDateTimeColumn HeaderText="Start Date" UniqueName="StartDate" DataField="StartDate" DataFormatString="{0:MM/dd/yyyy}">
            </telerik:GridDateTimeColumn>

column in the Batch Edit demos of RadGrid and test under iPad. 

Tap over RadTextBox, enter some new date and press Go/tap out and you'll see the problem.

The following concerns the editing of tables within RadEditor using the out-of-the-box Delete Row and Delete Column commands:
Delete Rows:
- Click in a cell.
- Click the Delete Row button. The row is deleted.
- The Delete Row button is still enabled, but when I click it nothing happens. The cursor is in the expected location and I'm able to immediately begin typing. However, I must again click in the cell for the Delete Row button to work.

Delete Columns:
- Click in a cell.
- Click the Delete Column button. The column is deleted.
- The Delete Column button is disabled. If I begin typing or click in the table it becomes enabled and functional again.

The end-user should be able to repeatedly click either button and have it work until there aren't any more rows or columns left to delete.

The following code will trigger the issue:
<ins author="Test user1" command="Insert" timestamp="1488935783059" title="Inserted by Test user1 on 3/7/2017, 5:16:23 PM" class="reU7">
<p cssproperty="verticalAlign" author="Test User2" timestamp="1488945891760" title="Formatted by Test User2 on 3/7/2017, 8:04:51 PM" class="reFormat reU0" command="Remove alignment"><span style="font-size: 12pt;">&nbsp;</span><span style="font-size: 12pt; font-family: 'Times New Roman';">This is some sample text.</span></p>
</ins>
When track changes are enabled and you try to delete from the end of this text, the deleted characters move to the following lines with a strikethrough rather than just deleting.