How to reproduce: enabled High DPI scaling and create a form as an MDI child with a RadDataEntry control in it
Workaround:  handle the Shown event of the MDI child and manually perform the scaling
private void radButtonElement1_Click(object sender, EventArgs e)
        {
            var view = new RadForm1
            {
                MdiParent = this
            };
            
            view.Shown += View_Shown;
            view.Show();
        }

        private void ScaleRadControls(Control c)
        {
            foreach (var item in c.Controls)
            {
                Control control = item as Control;
                if (control == null)
                {
                    continue;
                }

                this.mi.Invoke(control, new object[] { this.FormElement.DpiScaleFactor, BoundsSpecified.All });
                ScaleRadControls(control);
            }
        }

        MethodInfo mi;
        private void View_Shown(object sender, EventArgs e)
        {
            this.mi = typeof(Control).GetMethod("ScaleControl", BindingFlags.Instance | BindingFlags.NonPublic, null, new Type[] { typeof(SizeF), typeof(BoundsSpecified) }, null);
            RadForm1 v = sender as RadForm1;
            if (v != null)
            {
                ScaleRadControls(v.radDataEntry1.PanelContainer);
            }
        }

To reproduce: please refer to the attached sample project and gif file.

Workaround: use screentips: https://docs.telerik.com/devtools/winforms/telerik-presentation-framework/tooltips-and-screentips/screen-tips

One should be able to persist to a file all changes made when using the element hierarchy editor at design time.

It will be nice if one can add his custom sub menu items at design-time through the 'Add new item' menu. This was supported in the past, but the support was removed together with the introduced design-time optimizations.

Currently the sgen tool raises an exception when executing it on RadControls and RadControls.UI. There is also an XmlSerialization exception when  loading the application.

One should be able to export to a stream instead to a file as well.

To reproduce:
- Drag RadDropDownList control on a form, expand its DropDownListElement property, and change the ItemHeight
- Another case is, on a RadForm, expand FormElement>TitleBarElement and set its Visibility to Collapsed

Workaround: set the desired property at runtime
radDropDownList1.DropDownListElement.ItemHeight = 22;

Steps to reproduce:
1. Drag a grid on the form
2. Drag one or more controls over the grid - at this point in the Document Outline you can see the dragged control is a child of the grid
3. Open the Property Builder of the grid and close it - at this point the dragged control disappears

Workaround:
1. Open the Designer.cs file, and locate the line, where the control is added to the grid e.g.
            this.radGridView2.Controls.Add(this.radButton4);
and change it to:
            this.Controls.Add(this.radButton4);

If need be, set the Location property of the control at design time, to position it at the desired place.

2. Alternatively, you can place the control outside the grid bounds and after selecting it, use the arrow keys to position is over the grid. This will not make it its child, hence the issue will not appear.

To reproduce:

Create a RadForm and add a RadButton. Open the Element Hierarachy Editor and set the ShowBorder of the RadButtonElement to false. Another way is to set the ShowBorder property through the Properties section in Visual Studio. Save the form, close it and reopen it. You will see that the border is shown  and the property is set to true.

Workaround:

Set the value at runtime:

this.radButton1.ButtonElement.ShowBorder = false;

RadControls are slow when using at design time in a form containing a lot of controls, split containers and table layout panels

To reproduce: 
1. Drag and drop RadPageView on the form
2. Add 2-3 pages 
3. Set the ViewType to Backstage
4. Open smart tag and press Delete key to edit the Item Area Width property. 
After pressing the key, the RadPageView is removed from form.  

The issue is observed in Visual Studio 2015 only. 

1.Drag a RadGridView to a form
    2.Click Dock in parent from its SmartTag menu
    3.Now change the Dock to None from the Properties window
    4.Open again the smart tag and you will see that the link's text is "Undock in parent container" but the control is not docked.

The same issue occurs with all controls that have "Dock in parent container" action link.

To Reproduce: 
1. Install Q2 2015 (version 2015.2.623) of Telerik UI Winforms on PC with Visual Studio 2008 
2. Start the VS2008 and create new VB Winforms project 
3. Drag and drop from toolbox any control (RadButton or RadGridView). 
4. Open smart tag and click Edit UI Elements 
5. Message box with error is shown 

Workaround: 
If is possible use Visual Studio 2010 or higher version.

Workaround: manually resize the editor or drag it upwards 

As workaround please, rename the controls with Find & Replace from VS Editor.