Our application embed a RadDock element.Unfortunately, in a non-systematic way, our application crash with this stack trace: 

Our application is a 64bit application (we migrated it to NET6 using Telerik 2022.2.510.60). As I told unfortunately in this case I'm not able to isolate the case in a simple project (as I'm used to to).

It would be useful by your side, however, make a check to the last trace line of the log I've gave to you: 

 at Telerik.WinControls.UI.ThemedFormBehavior.OnWMNCHitTest(Message& m)

If I decompile your code I find this:

L_param, returned in (1) is an IntPtr that, on a 64bit machine running a 64bit application could contains a value that SOMETIMES will crash in (2) where you try to convert it with an IntTo32 method...

99 time to 100 the code in line 755 works fine but I think that it is not guaranteed that L_Param returned in (1) can be fit in a 32bit box. This could explain why I use the phrase "...in a very random way" and why, at the moment, I'm not be able to give you a simple application where the problem is systematic.

I suspect that at line 755 we have got a problem, I'll appreciate your point of view about it.

Use attached to reproduce.

Tested on Windows 10 (1607 and 1703)

Workaround:

RadControl.EnableDpiScaling = False

In addition, if this ContextMenu is called from a control contained in an autohide DockWindow that is currently expanded, this window becomes collapsed.

To reproduce:
Use the approach here:  http://docs.telerik.com/devtools/winforms/dock/object-model/customizing-floating-windows

Workaround:
private void RadDock1_FloatingWindowCreated(object sender, Telerik.WinControls.UI.Docking.FloatingWindowEventArgs e)
{
    e.Window = new MyWindow(radDock1);
    e.Window.FormBorderStyle = System.Windows.Forms.FormBorderStyle.Sizable;

}

class MyWindow : FloatingWindow
{
    public MyWindow(RadDock dock): base(dock)
    {

    }
    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams cp = base.CreateParams;
            cp.Style |= NativeMethods.WS_THICKFRAME;
            return cp;
        }
    }
}

I put a tree on toolwindow (the tree Nodes are chekbox)  , when I autohide the toolwindow and show it again the font of tree nodes change and also the nodes which were checked change to uncheck

We have a somewhat complicated application in which we have a RadDock inside another RadDock.
Everything seems to work just fine, with one exception.

When we resize the application window itself, the ToolWindow and DocumentWindow controls don't properly redraw their areas..

If there is a RadDock in UserControl and second UserControl, which inherits the first one, then the RadDock€™s layout in the second UC is damaged in design and run-time.

It is caused when you open the solution for the first time, open the FrmUmre in design time, change the active window in RadDock and run the application. 

The error states: "The control Telerik.WinControls.UI.Docking.DocumentTabStrip has thrown an unhanded exception in the designer and has been disabled"

FIX. RadDock - with two nested docks, setting the DocumentTabsAlignment of the other dock automatically sets the same on the inner one and this cannot be changed. Once you change it and reload the design time, its setting is being reset.

To reproduce 
- add RadDock with couple DocumenWindows in it
- add second RadDock with coupld DocumentWindows in it, in one of the windows of the first dock
- set Raddock2 DoumentTabsAlignment to top
- set DocumentTabStrip2 TabStripAlignment also to top or default
- drag a radbutton into documentwindow3 and double click it, to get a click event
- go into code view and remove the created event manually
- change back to form view. the alignment in DocumentTabStrip2 has been automatically changed to bottom

Dock windows should keep its icon and image that is set for them in a previous state, no matter their form, tabbed, docked,

To reproduce:
- Add 2 DockWindows and dock it Add about 10 controls in one of the windows. AutoHide them and show them one after another, you will notice that the old one is visible somewhere in the middle of the animation.
- Also you will notice that AutoHideWindowDisplayed and AutoHideWindowDisplaying events are fired twice.

Hidden HostWindows are not loaded correctly when the load operation is performed twice.

1. Create a new project with RadDock and add 5 tool windows.
2. Dock all tool windows to bottom.
3. Reset the order of the tool windows to not be 1-5
4. Set the group to auto-hide
5. Save dashboard layout
6. Load dashboard layout

1. Create a project with RadDock.
2. Add several tool windows.
3. Run the project.
4. Auto hide all tool windows at the bottom.
5. Close the last tool window.
6. Save the layout.
7. Load the layout.

The issue is reproduced when the Theme service of Windows is stopped and classic windows desktop is used

I have issues with Databindings for RadToggleButton and RadDock ToolWindow.

Here are 3 scenarios to try with my repro application.

ToggleButton
Click the radToggleButtonElement1, notice that the binding never occurs.

ToolWindow Docking issue 1
Dock the toolWindow1 to the left over ToolWindow2
Click toolWindow2
Click toolWindow1
Click toolWindow2
Notice each time you click another tool window, the binding is triggered even if the property value hasn't changed.

ToolWindow Dockin issue 2
Dock the toolWindow1 to the left over toolWindow2
Notice that the binding is triggered, but with the previous value (Floating instead of Docked)
close the toolWindow1
Notice that the binding is triggered, but with the previous value (Docked instead of Hidden)

The DocumentTabStrip raises the SelectedIndexChanging event twice

These are the steps to reproduce the bug:

1. Start dragging a docked window tab (but don't leave the tab bounds for now).
2. While still holding the left mouse button, click the right mouse button to let the context menu appear.
3. Now drag the tab outside the tab bar until the window gets undocked (for example to the blue region above the docked windows).
4. Finish dragging by releasing the left mouse button.
5. Move the mouse cursor over the title bar of another docked window -> the window is undocked without interacting with it and will stick to the cursor until you click the mouse button to release it.

Workaround:
   bool flag = false;
        public Form1()
        {
            InitializeComponent();
            
            ContextMenuService menuService = this.radDock1.GetService<ContextMenuService>();
            menuService.ContextMenuDisplaying += menuService_ContextMenuDisplaying;

            DragDropService service = this.radDock1.GetService<DragDropService>();
            service.Starting += service_Starting;
        }

        void service_Starting(object sender, StateServiceStartingEventArgs e)
        {
            e.Cancel = flag;
            flag = false;
        }

        void menuService_ContextMenuDisplaying(object sender, ContextMenuDisplayingEventArgs e)
        {
            flag = true;
        }

How to reproduce: check the attached project and video

Workaround:
public partial class RadForm1 : Telerik.WinControls.UI.RadForm
{
    public RadForm1()
    {
        InitializeComponent();
        radDock1.FloatingWindowCreated += RadDock1_FloatingWindowCreated;
    }

    private void RadDock1_FloatingWindowCreated(object sender, Telerik.WinControls.UI.Docking.FloatingWindowEventArgs e)
    {
        e.Window = new MyWindow(this.radDock1);
    }
}

public class MyWindow : FloatingWindow
{
    SizeF oldDpi = new SizeF(1, 1);

    public MyWindow(RadDock dockManager) : base (dockManager)
    { }
    protected override void HandleDpiChanged()
    {
        
        base.HandleDpiChanged();
        SizeF descale = new SizeF(1f / this.FormElement.DpiScaleFactor.Width, 1f / this.FormElement.DpiScaleFactor.Height);
        this.Scale(descale);
        var dpi = NativeMethods.GetMonitorDpi(Screen.FromRectangle(this.Bounds), NativeMethods.DpiType.Effective);
        if (oldDpi != dpi)
        {
            SizeF sz = new SizeF(dpi.Width / oldDpi.Width, dpi.Height / oldDpi.Height);

            this.Scale(dpi);
        }

        oldDpi = dpi;
    }
}

To reproduce:
- Add 2 RadFoms to a raddock in mdi mode.
- Dock the windows by using the left or right docking guide in the center.
- You will notice that the behavior is the same as like using the left or right side guides.