To reproduce:
- Drop RadMarkupDialog on the form
- In code set its DefaultFont and show it

WORKAROUND:
Create an instance of RadMarkupDialog prior showing it, not at design time.

Html formatting does not work as expected in design-time.

To reproduce:
- Try to set the  alignment:
radPopupEditor1.PopupEditorElement.PopupContainerForm.HorizontalPopupAlignment = HorizontalPopupAlignment.RightToRight;
radPopupEditor1.Popup.HorizontalPopupAlignment = HorizontalPopupAlignment.RightToRight;

- The property is reset when the popup is opened.

Workaround:
void radPopupEditor1_PopupOpening(object sender, CancelEventArgs e)
{
    RadPopupOpeningEventArgs args = e as RadPopupOpeningEventArgs;
    int width = radPopupContainer1.Width;

    args.CustomLocation = new Point(args.CustomLocation.X - width + radPopupEditor1.Width, args.CustomLocation.Y);
}

When you focus a RadTextBox you will notice the keyboard button that popups next to the focused control. However, for the RadAutoCompleteBox this keyboard button does not show.

Workaround: show it manually on the GotFocus event and hide it on the LostFocus event 

private void radTextBox1_GotFocus(object sender, EventArgs e)
{
    string progFiles = @"C:\Program Files\Common Files\Microsoft Shared\ink";
    string keyboardPath = Path.Combine(progFiles, "TabTip.exe");
    Process.Start(keyboardPath);
}
 
private void radTextBox1_LostFocus(object sender, EventArgs e)
{
    var procs = Process.GetProcessesByName("TabTip");
    if (procs.Length != 0)
        procs[0].Kill();
}

To reproduce:
this.radTextBoxControl1.Text = "dog and blue glue";
this.radTextBoxControl1.Size = new Size(50, 65);
this.radTextBoxControl1.Multiline = true;

Workaround:
use RadTextBox.

To reproduce:
public Form1()
{
    InitializeComponent();

    this.radTextBox1.Text = "abcd";
    this.radTextBox2.Text = "abcd";
    this.radTextBoxControl1.Text = "abcd";
    this.radTextBoxControl2.Text = "abcd";

    this.radTextBox2.Multiline = true;
    this.radTextBoxControl2.Multiline = true;

    this.textBox1.Text= "abcd";
    this.textBox2.Text= "abcd";
    this.textBox2.Multiline = true;
}

Workaround: set the Multiline property to true in the Form.Load event.

Second workaround: this.radTextBox2.TextBoxElement.TextBoxItem.Margin = new Padding(-2, 0, 0, 0);

Use attached to reproduce:
- Disable and then enable the RadSateTimePicker
- You will notice that even the checkbox is unchecked the control is enabled. 

Workaround:

radDateTimePicker1.Enabled =true;
if (!radDateTimePicker1.DateTimePickerElement.Checked)
{
    radDateTimePicker1.DateTimePickerElement.TextBoxElement.TextBoxItem.HostedControl.Enabled = false;
}

To reproduce: please refer to the attached sample project and follow the steps from the provided gif file.

Workaround: use RadTextBoxControl.

This behavior can be observed in the Office2010 theme. In the following image, the button's width in RadCalculatorDropDown and RadSpinEditor is less by 1 px compared to the buttons in the other editor controls.

Sample code to reproduce the case: 

            if (int.TryParse(txtCount.Text, out int count))
            {
                string textToSet=new string('A', count)+"END";
                txtSample.Text = textToSet;

                this.radTextBox1.MaxLength = textToSet.Length;
               
                this.Text = txtSample.Text.Length.ToString();
               
            }

To reproduce: use Korean (Microsoft IME) keayboard 
this.radTextBoxControl1.ImeMode = System.Windows.Forms.ImeMode.Hangul;


Workaround:
this.radTextBoxControl1.KeyUp+=radTextBoxControl1_KeyUp;

private void radTextBoxControl1_KeyUp(object sender, KeyEventArgs e)
{
    this.radTextBoxControl1.SelectionStart = this.radTextBoxControl1.Text.Length;
}
Note: the issue can be also observed in the textbox editor in RadGridView.

Currently, you cannot enter the date in RadDateTimePicker by typing it in the textbox area.

Use attached project and the following steps:
- When the application starts, use the drop down calendar to select another date.
- Then press Ctrl+A to select the entire content of the editor and press the Del key to clear the content.
- Now press the right arrow key and it crashes with a NullReferenceException inside of the RadDateTimePickerElement.OnKeyDown method.
-  This bug only occurs when ShowCheckBox is true.

Workaround:
class MyRadDateTimePicker : RadDateTimePicker
{
    protected override RadDateTimePickerElement CreateElement()
    {
        return new MyRadDateTimePickerElement();
    }
}
class MyRadDateTimePickerElement : RadDateTimePickerElement
{
    protected override void OnKeyDown(KeyEventArgs e)
    {
        var provider = this.TextBoxElement.Provider as MaskDateTimeProvider;
        if (e.KeyCode == Keys.Right && provider.List != null)
        {
            base.OnKeyDown(e);
        }

    }
    protected override Type ThemeEffectiveType
    {
        get
        {
            return typeof(RadDateTimePickerElement);
        }
    }
}

To reproduce:
- Disable the control.
- The text box has a white background.

- Workaround:
Set the  back color of the RadTimeMaskedEditBoxElement in for the disabled state in Visual Style Builder. 

To reproduce:
-add a GridViewDateTimeColumn to a RadGridView.
-try to set RadDateTimeEditor.MaxValue in CellEditorInitialized event to 31/12/9999. As a result ArgumentOutOfRangeException("MaxDate cannot be higher than the max date") is thrown

The new functionality should prevent duplicates to be added as tokens in the editor. An already selected item should not be visible in the popup as well. 

The attached 1148813-AutocompleteDuplicates.zip project features a possible custom solution. 

When you drag a RadDateTimePicker from the Toolbox and drop it onto the form, the TabStop property is false by default. If you change it in the Properties grid to true and save the form, try to open the form designer again. As a result the TabStop property is set to false as if no changes have been performed.

You need to press Tab twice to move to the next control when in popup editor.

Use attached to reproduce.