The TimePickerElement of RadTimePicker does not expose any events. However, events are needed if one needs to use this picker as an element, let's say in RadRibbonBar.

Select a date from RadDateTimePicker using the calendar dropdown. Now type another date in the textbox to make a new selection. Open the drop-down and you will see that there are two dates 'selected'. The issue occurs, because when you select from the calendar, you set the cell to Focused.Selected. When you then type a date in the textbox, you change the Focused cell, but the selection on the previous cell remains. So, you end up with two 'selected' cells. The workaround is to clear the selection on opening the dropdown: 

        void radDateTimePicker1_Opening(object sender, CancelEventArgs e)
        {
            calendar.SelectedDates.Clear();
        }

To reproduce:
radDateTimePicker1.ShowUpDown = true;

WORKAROUND:
            radDateTimePicker1.ShowUpDown = true;
            radDateTimePicker1.Enabled = false;
            radDateTimePicker1.Enabled = true;

To reproduce:
            radTimePicker1.Enabled = false;
            radTimePicker1.Enabled = true;

WORKAROUND:
 void radTimePicker1_EnabledChanged(object sender, EventArgs e)
{
    if (radTimePicker1.Enabled)
    {
        radTimePicker1.TimePickerElement.ForeColor = Color.Black;
    }
}

Fix suggest behavior in RadAutoCompleteBox to support spaces in the written text.

WORKAROUND:
public class MyAutoCompleteBox : RadAutoCompleteBox
    {
        public MyAutoCompleteBox()
        {
            this.ThemeClassName = typeof(RadAutoCompleteBox).FullName;
        }

        protected override RadTextBoxControlElement CreateTextBoxElement()
        {
            return new MyAutoCompleteBoxElement();
        }
    }

 public class MyAutoCompleteBoxElement : RadAutoCompleteBoxElement
    {
        protected override Type ThemeEffectiveType
        {
            get { return typeof(RadAutoCompleteBoxElement); }
        }

        public override void CloseDropDown(RadPopupCloseReason reason)
        {
            if (reason == RadPopupCloseReason.CloseCalled)
            {
                if (this.ListElement.SuggestedText != null && this.ListElement.PatternText != null && this.ListElement.IsSuggestionMatched)
                {
                    return;
                }
            }

            base.CloseDropDown(reason);
        }

        protected override RadTextBoxListElement CreateListElement()
        {
            return new RadTextBoxListElement();
        }
    }

The RadAutoCompleteBox does not show its dropdown when single item is suggested.

RadTextBoxControl - you can not type more than one polish char -"Ä…". 

Steps to reproduce:

Change keyboard to Polish(programmers)
Type "Ä…" while pressing right alt.

Workaround:
Use RadTextBox instead RadTextBoxControl.

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.

Steps to reproduce:

1. Set a Standard Mask on the RadMaskedEditBox and a space a PromptChar.
2. Type some text in the RadMaskedEditBox.
3. Press the "Home" key to move the cursor at the beginning of the RadMaskedEditBox.
4. Then press the spacebar.
5. You should see the first character gets deleted but instead of leaving a space in the first position in the RadMaskedEditBox, the second character is moved in the first position and the cursor is on the second position.

If you press the spacebar again the space is entered in the RadMaskedEditBox and the cursor potition is ok.

steps to reproduce:

 - Click on the red cross to delete the "radAutoCompleteBox1" entry of the first RadAutoCompleteBox.    The blinking cursor is positioned at the beginning of the box.
 - Click on the second RadAutoCompleteBox.
The blinking cursor is positioned in the second box, but the blinking cursor of the first RadAutoCompleteBox is still present.

Drop RadTextBox on the form - there is a default text which equals to the Name of the control.

The RadMaskedEditBox wil throw an exception if set the custom culture with empty CurrencySymbol and MaskType is set to Numeric. 

Workaround:
Set the CurrencySimbol to space char:

            cultureInfo.NumberFormat.CurrencySymbol = " "
            this.radMaskedEditBox1.Culture = cultureInfo

Use the TextChanged event instead

Multiply line text is not correct align at the left side when control runs on Win xp.

Steps to reproduce:
this.radTextBoxControl1.Text = "This\nis a\ntest";

Workaround:
((RadDateTimePickerCalendar)this.dtpFromTaarich.DateTimePickerElement.GetCurrentBehavior()).Calendar.Navigating +=
               new CalendarNavigatingEventHandler(dtp_Navigating);
 
void dtp_Navigating(object sender, Telerik.WinControls.UI.CalendarNavigatingEventArgs e)
       {
           if (e.Direction == Telerik.WinControls.UI.CalendarNavigationDirection.Forward)
           {
               if (!e.IsFastNavigation)
                   e.StartDate = (sender as RadCalendar).CalendarElement.View.ViewStartDate.AddMonths(-1);
               else
                   e.StartDate = (sender as RadCalendar).CalendarElement.View.ViewStartDate.AddMonths(-12);
           }
           else if (!e.IsFastNavigation)
           {
               e.StartDate = (sender as RadCalendar).CalendarElement.View.ViewStartDate.AddMonths(1);
           }
           else e.StartDate = (sender as RadCalendar).CalendarElement.View.ViewStartDate.AddMonths(12);
       }

Resolution: You need to set the RightToLeft property to Yes of CalendarBehavior
RadDateTimePickerCalendar calendarBehavior = this.radDateTimePicker1.DateTimePickerElement.GetCurrentBehavior() as RadDateTimePickerCalendar;
RadCalendar calendar = calendarBehavior.Calendar as RadCalendar;
calendar.RightToLeft = System.Windows.Forms.RightToLeft.Yes;

1. Create new project and add RadTextBox inside a user control.
2. Set its Dock property to Left.
3. Add custom button items in its layout by using RadButtonElement and StackLayoutElement.
4. Set a default value to the text box when handling the form Load event.
5. Run the project.

To reproduce:
 private void MdiChildForm_Load(object sender, EventArgs e)
 {
      radMaskedEditBox1.MaskType = MaskType.Numeric;
      radMaskedEditBox1.Mask = "n4";
      radMaskedEditBox1.NullText = "this is null text"
}
 private void radButton1_Click(object sender, EventArgs e)
{
      radMaskedEditBox1.Value = null;
 }

the issue appears also when the RadmaskedEditBox is configured like this:

this.radMaskedEditBox1.MaskType = Telerik.WinControls.UI.MaskType.Standard;
this.radMaskedEditBox1.Mask = "0000000";

this.radMaskedEditBox1.NullText = "My null text";
this.radMaskedEditBox1.PromptChar = '_';

WORKAROUND:
radMaskedEditBox1.Value = null;
radMaskedEditBox1.MaskedEditBoxElement.TextBoxItem.HostedControl.Text = "";

FIX. When we change the Culture property, the control will display the current date even if the value of the control is NULL

Workaround:
Set an empty string to the Hosted TextBox control after the Culture set.
For example:
radDateTimePicker1.Culture = Thread.CurrentThread.CurrentCulture;
radDateTimePicker1.DateTimePickerElement.TextBoxElement.TextBoxItem.HostedControl.Text = "";

RadMaskedEditBox - has incorrect behavior if you set values with differed length.

Workaround is to reset the value before to set new one:

C#
RadMaskedEditBox1.Value = null;
RadMaskedEditBox1.Value = "YourText";

VB
RadMaskedEditBox1.Value = Nothing
RadMaskedEditBox1.Value = "YourText"

Steps to reproduce.
1. Add a RadTextBoxControl and a button to a form
2. On the button click set a large text (the text from a 150KB text file) to the Text property of the text box.

You will see that the control takes a lot of time to complete the operation.