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. 

Use attached to reproduce.

Workaround:
RadTextBox tb = new RadTextBox();

tb.Font = new Font(Font.Name, 12F, FontStyle.Bold);

tb.MaxLength = 200;
tb.Name = "textBox1";
tb.Text = "<Required>";
tb.Location = new Point(49, 7);
var pixels = tb.Font.SizeInPoints * 96 / 72;
tb.TextBoxElement.TextBoxItem.HostedControl.MinimumSize = new Size(0, (int)pixels + 6);

Hello,

I have noticed a bug in the Autocompletebox.

When the Autocompletebox.Multiline is enabled and setting the text to an item with multiple delimiters where the items are shown on multiple lines (see image).

When clicking on one of the items in line 2 or 3, the value e.selectionstart returned on the Selectionchanged-event has a wrong value.

On line 2 the e.selectionstart is 1 too much

Imports Telerik.WinControls.UI

Public Class RadForm1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim str As String = "Item 1;Item 2;Item 3;Item 4;Item 5;Item 6;Item 7;Item 8;Item 9;Item 10;"
        RadAutoCompleteBox1.Multiline = True
        RadAutoCompleteBox1.Text = str

    End Sub

    Private Sub RadAutoCompleteBox1_SelectionChanged(sender As Object, e As SelectionChangedEventArgs) Handles RadAutoCompleteBox1.SelectionChanged
        Dim SelectedItem As String = RadAutoCompleteBox1.Text.Substring(e.SelectionStart, e.SelectionLength)
        Debug.Print(SelectedItem)
    End Sub
End Class

Set the format:

dateTimePicker1.Format = DateTimePickerFormat.Custom;
dateTimePicker1.CustomFormat = "dd/MM/yyyy";

Enter 18 in the yaer part, the year should be set to 2018, the year should be cleared when starting to type as well.

Workaround: use RadTextBoxControl.

Use attached to reproduce.
- Open the dialog multiple times.

To reproduce: add a RadSpellChecker and a RadTextBoxControl and set the RadSpellChecker.AutoSpellCheckControl property to the RadTextBoxControl. When you type "Thisis", the red underline appears, indicating the error. However, if you use the context menu to correct the misspelled word, the red underline remains. Please refer to the attached gif file.

Workaround: stop the default context menu and use the spell checking form instead:

private void radTextBoxControl1_ContextMenuOpening(object sender,TreeBoxContextMenuOpeningEventArgs e)
{
    e.Cancel = true;

    this.radSpellChecker1.Check(this.radTextBoxControl1);
}