Form goes under windows taskbar based on following conditions.

WindowState = Maximized

MinimizeBox = false

MaximizeBox = false

Also when there is no icon (ShowIcon = false) Form text, first letter is clipped.  

1.download and install the telerik trial version for ui winforms for desktop latest version 2019. 219.

2.open new project with blank template.

3.create radform and set Radform1 as mdi form. And open a child page from this..

CHild page takes 4 seconds to load. Though child page has only grid view and loads only 6000 records

To reproduce: on some Windows 10 machines the title bar's text is not rendered clearly. 

Workaround:

1. Set the RadForm.AllowTheming property to false.

2. In the form's Load event change the TextRenderingHint of the caption text primitive to AntiAliasGridFit:  

TextPrimitive tp = this.radRibbonBar2.RibbonBarElement.RibbonCaption.CaptionLayout.CaptionTextElement as TextPrimitive;
tp.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;

Please refer to the attached sample project.
 
Workaround: Initialize the form just before showing it.

To reproduce:
- Add 3 MDI child forms with a lot of gauges.
- Set their WindowState to maximized.
- Show each upon a button click.

Workaround:
Set the state of all forms to normal, before adding a new maximized form.

1. 2 Monitors configured. The primary display is 16:9 (laptop), the second display has an aspect ratio is 16:10 (desktop monitor).
2. move sample Telerik WinForm app to secondary display (desktop monitor)
3. Click on maximize button

Result: Application width is more then monitor size, as result application is truncated from right.

The same happens with "RadControls for WinForms Q1 2010 Demos" which I have installed on my PC

To reproduce: disable Aero on a Windows7 machine and use the following code:

public Form1()
{
    InitializeComponent();

    this.IsMdiContainer = true;

    Form MSform = new Form();
    MSform.Text = "Form MDI Child 1";
    MSform.MdiParent = this;
    MSform.Show();

    MSform = new Form();
    MSform.Text = "Form MDI Child 2";
    MSform.MdiParent = this;
    MSform.Show();
    
    MSform = new Form();
    MSform.Text = "Form MDI Child 3";
    MSform.MdiParent = this;
    MSform.Show();

    RadForm form = new RadForm();
    form.Text = "RadForm MDI Child 1";
    form.MdiParent = this;
    form.Show();

    form = new RadForm();
    form.Text = " RadFormMDI Child 2";
    form.MdiParent = this;
    form.Show();
    
    form = new RadForm();
    form.Text = " RadFormMDI Child 3";
    form.MdiParent = this;
    form.Show();
}

private void Form1_Shown(object sender, EventArgs e)
{
    this.LayoutMdi(MdiLayout.TileHorizontal);
}

private void radButton1_Click(object sender, EventArgs e)
{
    this.LayoutMdi(MdiLayout.TileVertical);
}

private void radButton2_Click(object sender, EventArgs e)
{
    this.LayoutMdi(MdiLayout.Cascade);
}

private void radButton3_Click(object sender, EventArgs e)
{
    this.LayoutMdi(MdiLayout.TileHorizontal);
}

Workaround: set the RadForm.AllowTheming property to false.

Workaround 2:  public class MyForm : RadForm
 {
     protected override CreateParams CreateParams
     {
         get
         {
             CreateParams par = base.CreateParams;
             par.Style |= NativeMethods.WS_CAPTION;
             return par;
         }
     }
 }

My company is in the process of moving to windows 10 and we have a handful of custom systems that have to be migrated. I was told to "Just make them work". One of those is a tool that was written in 2008 using all Telerik controls. This system was last updated in 2012 to run on windows 7. We have plans to move the functionality to a Universal App however, we have bigger fish to fry. here is a list of all the bugs we encountered so far:

Forms with tons of controls(170 in my case) take forever to Initialize(> 60 seconds) especially the RadDateTimePicker;

The UI freezes until the InitializeComponent method  completes. 

The forms occasionally throws timeout errors waiting on a Com Handoff for more then 60 seconds.

There is no databinding going on and there is no functionality tied to the initialization or loading of the forms in an MDI. Only Large forms have this problem.

Any form that executes the following code does not load:
this.RootElement.ApplyShapeToControl = true;

To reproduce:
- Add a menu item with a specific mnemonic key to a form.
- Add child form with a button that has the same mnemonic key.
- Start the application hold Alt and press the mnemonic key.
- The menu item is executed instaed of the

To reproduce:

private void radButton1_Click(object sender, EventArgs e)
{
    Application.Exit();
}

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    RadMessageBox.Show("Do you want to exit?", "Confirmation", MessageBoxButtons.YesNo);
}


Workaround: Show the RadMessageBox first and then call the Application.Exit method according to the DialogResult.

DECLINED: 
When Application.Exit() is called it iterates through all forms and for each of them calls the FormClosing event. Currently the RadMessageBox is shown in a new form. So in this case during the iterating forms collection a new form is added and this causes the exception "Collection was modified; enumeration operation may not execute.". 
This is expected behavior and there are two possible solutions to prevent application from throwing exception: 
- Use this.Close(); to close the application.
- Make your checks, show RadMessageBox and after that, if needed call Application.Exit(); 

it seems to be when I'm deriving from RadForm the NotifyPropertyChanged Doesn't seem to work

It is binding to the Text Propery of the dockwindow. what i am trying to do is bind to a propery of my class called FormText (This is not the Frm.Text but Frm.FormText) a completly diffrent property. This is not possible to do with the below code.

What I am ultimelty trying to do is have a class that is derived from RadForm so i can add a BindingSource to the form and load it with data.
I'm then trying to bind to the Possition and Item Count fo the BindingSource to show the user what record/how many records there are.

I need to re-bind this each time the tab is changed so the user is always seeing the records for the Selected form

Resolution: 
Scenario is not common and the issue is not related directly to our form. Since our RadForm is ISupportInitialize and in the case that the developer does not call Form EndInitialize method the Microsoft binding will reject the binding because Form IsInitialized property is false. So these methods must be called:
((System.ComponentModel.ISupportInitialize)(radForm1)).BeginInit();
((System.ComponentModel.ISupportInitialize)(radForm1)).EndInit();

FIX. RadForm - setting the CancelButton property of the form to a button named exactly CancelButton, will prevent the button click event from firing when Esc is pressed. Changing the name of the button anything else will resolve the case.
Comment: This is the default beavior of the standard button and comes from .NET Framework.