Create a custom theme starting from Aqua theme. Change the Font for RadLabelElement-TextPrimitive to "Microsoft Sans Serif, 10pt". Save the theme and apply it to the entire application. Show several times a RadMessageBox with long text. The first time the RadMessageBox is sized correcly to its content. Each next showing, cuts off the text.

Workaround:  the possible workaround that I can suggest is to dispose the RadMessageBox instance after showing it:

Private Sub RadButton1_Click(sender As Object, e As EventArgs) Handles RadButton1.Click
    RadMessageBox.Show(Me, "If you have some veeeeery long sample text, the messagebox " & _
                       "should be resized according to its content.", "Caption", MessageBoxButtons.OK, My.Resources.image)
    RadMessageBox.Instance.Dispose()
End Sub

Form should be closed only with Left mouse button

When the RadForm is used as MDI Child hosted by RadDock, the rendering of the form is not appropriate.

The size of RadForm under Windows XP is incorrect when its initial state as MDI child is Maximized and after that the state is changed to Normal.

Workaround:
Imports Telerik.WinControls.UI

Public Class BaseRadForm
    Inherits RadForm 

    Private Shared LastWindowState As FormWindowState = FormWindowState.Normal
    Private Shared suspendClientSizeChangedFlag As Boolean = False
 
    Protected Overrides Sub OnResizeBegin(ByVal e As System.EventArgs)
        Me.MaximumSize = New Size(0, 0)
        MyBase.OnResizeBegin(e) 
    End Sub
     
    Protected Overrides Sub OnActivated(ByVal e As System.EventArgs)
        Me.MaximumSize = New Size(0, 0)
        MyBase.OnActivated(e)
    End Sub

    Protected Overrides Sub OnDeactivate(ByVal e As System.EventArgs)
        Me.MaximumSize = New Size(0, 0)
        MyBase.OnDeactivate(e)
    End Sub

    Protected Overrides Sub OnClientSizeChanged(ByVal e As System.EventArgs)
        Dim osInfo As System.OperatingSystem = System.Environment.OSVersion
        If (suspendClientSizeChangedFlag OrElse osInfo.Version.Major >= 6) Then
            Return
        End If

        If Not LastWindowState.Equals(Me.WindowState) Then
            LastWindowState = Me.WindowState
            If Me.WindowState.Equals(FormWindowState.Normal) Then
                suspendClientSizeChangedFlag = True
                Me.MaximumSize = New Size(500, 500)
                suspendClientSizeChangedFlag = False
            ElseIf Me.WindowState.Equals(FormWindowState.Maximized) Then
                Me.MaximumSize = New Size(0, 0)
            End If
        Else
            Me.MaximumSize = New Size(0, 0)
        End If

        MyBase.OnClientSizeChanged(e)

    End Sub


End Class

To reproduce:
1. Drop a RadGridView and RadButton on Rad Form.
2. Set gris Anchor property to Top-Right-Bottom-Left and the buttons Anchor property to Right-Bottom.
3. Make sure that the RadForm's size is exactly as your desktop resolution(e.g. my 'RadForm' size and desktop resolution are 1920x1080).
4. Change its 'AutoScaleMode' property's value to 'Font'.
5. Build project.
6. Copy the resulted executable on your desktop and name it 'RadControlsWinFormsApp_Font'
7. Select again the RadForm.
8. Change its 'AutoScaleMode' property's value to 'DPI'
9. Build project.
10. Copy the resulted executable on your desktop and name it 'RadControlsWinFormsApp_DPI'
11. Select again the RadForm
12. Change its 'AutoScaleMode' property's value to 'Inherit'
13. Build project
14. Copy the resulted executable on your desktop and name it 'RadControlsWinFormsApp_Inherit'
15. Change your desktop resolution to a lower one (e.g. I've change it from 1920x1080 to 1600x900)
16. 'Auto-Hide' the Window's taskbar
17. Run the executables and see the results:
   17.1 In case of 'RadControlsWinFormsApp_Font' application, you should see that the 'RadGridView' control gets truncated + the lower right 'RadButton' is not visible anymore
   17.2 In case of 'RadControlsWinFormsApp_DPI' application, you should see that the 'RadGridView' control gets truncated + the lower right 'RadButton' is not visible anymore
   17.3 In case of 'RadControlsWinFormsApp_Inherit' application, you should see the controls on the form as you initially placed them.

Also this issue appears on 'Windows XP SP3 x86' and also on 'Windows 7 SP1 x64' .

Workaround:
- Set AutoScaleMode property to None or Inherit.

1. Create RadRibbonForm and add code to start maximized 
2. Add status strip with some items on the ribbon form 
3. in the form constructor create a MDI child form, set it to start maximized and show it 
4. The result is that there is gap between the child form and the status strip

Workaround:
protected override void OnShown(EventArgs e)
{
    base.OnShown(e);
 
    this.WindowState = FormWindowState.Minimized;
    this.WindowState = FormWindowState.Maximized;
}

On Windwos XP , Windows Vista, Windows 7 the RadForm/ShapedForm hides the taskbar when it is set to Auto-Hide. When you try to show the taskbar it appears behind (under) the RadForm instead of infront (over) it.

To reproduce:
- Add RadForm
- Set RightToLeft = True
- Click the form icon (the title bar icon) => the menu appears on the left side of the form instead of the right side. And also the menu is not in right to left mode.

To reproduce:
- Add four buttons to a RadForm
- On each button click use ThemeResolutionService to change the theme
=> the form size increases in height

Workaround:
Set the MaximumSize of the form to the current form size prior changing the theme and then remove this setting:
private void radButton1_Click(object sender, EventArgs e)
{
    this.MaximumSize = this.Size; ;
    ThemeResolutionService.ApplicationThemeName = "Office2010Blue";
    this.MaximumSize = Size.Empty;
}

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;

There should be an option to show a help button at the titlebar part of RadForm

UPDATED: this is reproducible in a non-MDI scenario is well.

Sub New()
    InitializeComponent()
    Me.Size = New Size(500, 500)
End Sub


To reproduce:

1. Add two RadForms - a parent and a child.
2. Set the MinimumSize property of the child form at design time.
3. Use the following code snippet:

public partial class ParentForm : RadForm
{
    public ParentForm()
    {
        InitializeComponent();

        this.IsMdiContainer = true;

        ChildForm form = new ChildForm();
        form.Text = "MDI Child 1";
        form.MdiParent = this;
        form.Size = new System.Drawing.Size(600, 600);
        form.Show();
    }
}

public partial class ChildForm : Telerik.WinControls.UI.RadForm
{
    public ChildForm()
    {
        InitializeComponent();
        this.SizeChanged += ChildForm_SizeChanged;
    }
    
    private void ChildForm_SizeChanged(object sender, EventArgs e)
    {
        this.Text = "ChildForm " + this.Size.Width + " x " + this.Size.Height;
    }
}

When you run the application with version 2015.2 623, you will notice that the child form is loaded with its MinimumSize. However, in the previous version it is loaded with the expected specified Size(600, 600).

Workaround: use ShapedForm with titlebar. An alternative solution is to set the RadForm.Size property in the Shown event.

To reproduce:
- Add two buttons and a textbox to a RadForm.
- Set the AcceptButton to be the first button.
- Focus the second button and press Enter

Workaround:
protected override bool ProcessCmdKey(ref System.Windows.Forms.Message msg, System.Windows.Forms.Keys keyData)
{
    if (keyData == System.Windows.Forms.Keys.Enter)
    {
        if (this.ActiveControl is Button && this.ActiveControl != this.AcceptButton)
        {
            ((Button)this.ActiveControl).PerformClick();
            return true;
        }
        
    }

    return base.ProcessCmdKey(ref msg, keyData);
}

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: 
- Start the narrator, open a message box and close it fast.
 
Workaround:
void button_Click(object sender, EventArgs e)
{
    RadMessageBox.Instance.Shown += Instance_Shown;
    RadMessageBox.Show("test");
}

void Instance_Shown(object sender, EventArgs e)
{
    RadMessageBoxForm form = sender as RadMessageBoxForm;

    typeof(RadMessageBoxForm).GetField("accObjectCreated", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance).SetValue(form, false);
}

To reproduce: 
- Use the approach described here to localize the form: https://msdn.microsoft.com/en-us/library/y99d1cd3%28v=vs.100%29.aspx?f=255&MSPPError=-2147217396
- Open the resx file in Visual Studio.

Broken in Q2 2015

Workaround: get current dpi settings and resize the form
float dpiX = 0;
float dpiY = 0;
Graphics graphics = this.CreateGraphics();
dpiX = graphics.DpiX;
dpiY = graphics.DpiY;

this.Width *= dpiX / 96;
this.Height *= dpiY / 96;

If you have a TextBox anchored to Top, Left, Right in a RadForm, the size that this TextBox gets when the form is shown may not be correct.

Workaround:
set the Dock = Fill setting after adding the controls/toolwindows in the forms

To reproduce:
1.Add a RadButton and on its Click event, show a RadMessageBox.
2.Add a RadDropDownList .
3.Drag several themes from the toolbox and drop them onto the form (e.g. Office2010Black, Office2010Blue, TelerikMetro, Windows8)
4.Use the following code:

public Form1()
{
    InitializeComponent();

    this.radDropDownList1.Items.Add("Office2010Black");
    this.radDropDownList1.Items.Add("Office2010Blue");
    this.radDropDownList1.Items.Add("TelerikMetro");
    this.radDropDownList1.Items.Add("Windows8");

    this.radDropDownList1.SelectedIndexChanged += radDropDownList1_SelectedIndexChanged;
    this.radDropDownList1.SelectedItem = this.radDropDownList1.Items[0];
}

private void radDropDownList1_SelectedIndexChanged(object sender,
    Telerik.WinControls.UI.Data.PositionChangedEventArgs e)
{
    string itemText = this.radDropDownList1.Items[e.Position].Text;           
    ThemeResolutionService.ApplicationThemeName = itemText;
}

private void radButton1_Click(object sender, EventArgs e)
{
    RadMessageBox.Show("Some message", "Confirmation", MessageBoxButtons.OKCancel);
}

When you select a new item from the RadDropDownList, the theme for the entire application is changed. But when you click the button to show a RadMessageBox, the RadMessageBox has incorrect style for its buttons.

Workaround: set the RadMessageBox.ThemeName before showing it:

RadMessageBox.ThemeName = ThemeResolutionService.ApplicationThemeName;
RadMessageBox.Show("Some message", "Confirmation", MessageBoxButtons.OKCancel);

If you have a RadForm that contains a RadTextBox (TextBox), set the WindowsState of this form to Maximized and add this form to an MDI Parent with RadDock which handles the forms, you will notived that you are not able to mouse select the text.