Setting the TextWrapping to Wrap or WrapWithOverflow will not allow the WatermarkContent to be wrapped.

Reason for decline: 

Instead of setting the content inline, we recommend setting it as follows: 

<telerik:RadWatermarkTextBox Width="100">
	<telerik:RadWatermarkTextBox.WatermarkContent>
		<TextBlock TextWrapping="Wrap" Text="Watermark Content Watermark Content Watermark Content Watermark Content" />
	</telerik:RadWatermarkTextBox.WatermarkContent>
</telerik:RadWatermarkTextBox>

More information can be found in our help about using the WatermarkContent and WatermarkTemplate properties: https://docs.telerik.com/devtools/wpf/controls/radwatermarktextbox/features#using-the-watermarkcontent-property
Please let us know if this is not applicable in the scenario of your application.

Similar to File Explorer in Windows 10, it would be helpful to have a Quick Access section in the left navigation pane with the ability to pin frequently used items.

File explorer with the drag and drop upload and just a richer interface

A component to easily chat with visitors on a website.  It's becoming popular to be able to interact and offer support that way.  Maybe based on the Windows Live Components or something along those lines.

When both horizontal and vertical ScrollBars are visible in Fluent theme, the "BottomHandle" RepeatButton cannot be pressed as it is overlapped by the horizontal ScrollBar on MouseOver. 

Default behavior will be changed and the scrollbars will be reordered in the ScrollViewer ControlTemplate so on MouseOver the current ScrollBar will have higher Canvas.ZIndex. 

look the attach file.

Controls are not visible in design-time when the build platform is x64.

Would it be possible to add a new theme that accurately tracks the Google Material Design guidelines?  (http://www.google.com/design/spec/material-design/introduction.html).

Available in the 2017 R2 Release.
More information you can find here: http://docs.telerik.com/devtools/wpf/styling-and-appearance/themes-suite/common-styling-appearance-material-theme

looking the attach file,when resize the second gridview's column moving back and forth when at first run the sample,the after columns flicker and the width grow and lessen.and when resize the third column,the 'unit price' column will become the min width.
but when test the microsoft's datagrid,it is good,the any other column width's change is gentle.

User can set AutoCalculateBounds to True by the following way:

 public class CustomClusterGenerator : DefaultClusterGenerator
    {
        public override ClusterData CreateCluster(Location center, object item)
        {
            var clusterData = base.CreateCluster(center, item);
            clusterData.AutoCalculateBounds = true;
            return clusterData;
        }
    }

  this.VisualizationLayer1.ClusterGenerator = new CustomClusterGenerator();

When clustering 4 points:

ObservableCollection<DataItem> items = new ObservableCollection<DataItem>()
            {
                new DataItem() {MapLocation = new Telerik.Windows.Controls.Map.Location(20, 30) },
                new DataItem() {MapLocation = new Telerik.Windows.Controls.Map.Location(20, 34) },

                new DataItem() {MapLocation = new Telerik.Windows.Controls.Map.Location(22, 32) },
                new DataItem() {MapLocation = new Telerik.Windows.Controls.Map.Location(18, 32) },
            };

            this.VisualizationLayer1.ItemsSource = items;

EXPECTED:  ClusterData's Bounds must  be:

WEST: 30 and EAST: 34.

Actual Values are 30 and 30 (29.9999 and 30).

Available in LIB version 2018.1.312.

When you start editing the input control, the watermark text should go on top of it or to the left.

It would be awesome if Telerik created custom OpenFileDialog, SaveFileDialog and BrowseFolderDialog controls/windows/dialogs that would mimic the functionality found in: Microsoft.Win32.

- Differentiate from competition - Create controls that other WPF controls packages don't have
- Allow users to have common styling/views across their application
- Make it so our software doesn't have to reference Microsoft.Win32, we can continue to have a native Telerik solution
- Could make it more intuitive to program with than the Microsoft dialog (with filters, startup folder etc)

Reference post:
http://www.telerik.com/forums/why-is-there-no-openfiledialog-in-telerik

Available in R3 2017 Official Release of UI for WPF.
Check what's new in R3 2017 here: 
http://www.telerik.com/support/whats-new/wpf/release-history/ui-for-wpf-r3-2017

You have, for example rectangle which is in ContentControl in XAML, next to FluidC.C.

FluidContentControl is in small state. Ona  button click SmallContent is assigned to the Rectangle.

This leads to the exception stated that rectangle is already a logical child of another element.

Basing on the "{StaticResource FilterControlStyle}" would cause an InvalidArgumentException, if the types would mismatch. 
If you are to base on a custom style on the default style of either of those controls, you can do it by type reference - e.g. BasedOn="{StaticResource {x:Type telerik:FilteringControl}}"

with windows10/2k DPI/14 inch screen ,when show the gridview gridline,the line is different.
     the other things,when the tabitem is selected,the dropdownmenu can't mark the selected item.
   look the attach files!