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.

Use the following code snippet:

            this.radMaskedEditBox1.Mask = "99/99/99/99/99/99";
            this.radMaskedEditBox1.MaskType = Telerik.WinControls.UI.MaskType.Standard;
            this.radMaskedEditBox1.PromptChar = ' ';
            ((StandartMaskTextBoxProvider)this.radMaskedEditBox1.MaskedEditBoxElement.Provider).TryGetStandardProvider().InsertKeyMode = InsertKeyMode.Overwrite;

When the cursor is just before the last "/", if you enter a number, then the cursor does not move after this last "/". Then entering another digit overwrites the last digit typed.

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

Workaround: use RadTextBoxControl.

To reproduce:
radPopupEditor1.PopupForm.VerticalPopupAlignment = VerticalPopupAlignment.TopToBottom;

Workaround:
private void RadPopupEditor1_PopupOpening(object sender, CancelEventArgs e)
{
    var args = e as RadPopupOpeningEventArgs;
    args.CustomLocation = new Point(args.CustomLocation.X, args.CustomLocation.Y - (radPopupEditor1.Height + radPopupEditor1.PopupForm.Height));
}

See attached video to reproduce.

Use attached to reproduce.

Workaround: 
Use RadTextBox.

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;
}

Windows TextBox - OSK perfect

Telerik RadTextBox - OSK perfect

Telerik RadTextBoxControl - OSK doesn't work

Telerik RadDropDownList - OSK doesn't work

Telerik AutoCompleteBox - OSK doesn't work

This should work for all controls that have text input.

The suggestion must popup after every word.
There should be an option for positioning the drop down inside the textbox.

 

Using UI for WinForms R3 2017 (version 2017.3.912)

Strange behavior while selecting text with the mouse, while TextAlign is set to Right and there is more text then visible.
To reproduce try selecting all the text in the control from the attached file (once to the left, once to the right).

If the ShowClear button is visible and RihtToLeft is true, it won't select to the left (while there is more text than visible).


RadTextBoxControl radTextBoxControl1 = new Telerik.WinControls.UI.RadTextBoxControl();

this.radTextBoxControl1.Location = new System.Drawing.Point(239, 186);
this.radTextBoxControl1.Name = "radTextBoxControl1";
this.radTextBoxControl1.RightToLeft = System.Windows.Forms.RightToLeft.Yes;
this.radTextBoxControl1.ShowClearButton = true;
this.radTextBoxControl1.Size = new System.Drawing.Size(64, 20);
this.radTextBoxControl1.TabIndex = 6;
this.radTextBoxControl1.Text = "123456789123456789";
this.radTextBoxControl1.TextAlign = System.Windows.Forms.HorizontalAlignment.Right;

To reproduce: please refer to the attached sample screenshots and project.

Note: this issue is relevant for RadDropDownList as well.

Workaround:             
            this.radDropDownList2.DropDownListElement.TextBox.TextBoxItem.Multiline = true;
            this.radDropDownList2.DropDownListElement.TextBox.TextBoxItem.MinSize  = new Size(30, 15); 

How to reproduce: also check the attached video
this.radMaskedEditBox1.MaskType = MaskType.Numeric;

Workaround:
private void RadMaskedEditBox1_TextChanged(object sender, EventArgs e)
{
    if (this.radMaskedEditBox1.Text == "-0")
    {
        if (this.radMaskedEditBox1.MaskedEditBoxElement.TextBoxItem.Text.Length == 2)
        {
            //Workaround
            this.radMaskedEditBox1.MaskedEditBoxElement.TextBoxItem.Text = this.radMaskedEditBox1.MaskedEditBoxElement.TextBoxItem.Text.Remove(1, 1);
        }
    }
}

The workaround in the following MSDN resources results in an incorrect behavior in the header of RadDateTimePicker: https://code.msdn.microsoft.com/Fixing-Persian-Locale-for-6e66e044#content

To reproduce:
 radTimePicker1.Value = DateTime.Now.AddDays(10);
 radTimePicker1.TimePickerElement.MaskedEditBox.MaskType = Telerik.WinControls.UI.MaskType.FreeFormDateTime;

Workaround:

protected override void OnLoad(EventArgs e)
{
    base.OnLoad(e);
    radTimePicker1.Value = DateTime.Now.AddDays(10);

    var provider = radTimePicker1.TimePickerElement.MaskedEditBox.Provider as FreeFormDateTimeProvider;

    provider.MinDate = DateTime.MinValue;
    provider.MaxDate = DateTime.MaxValue;
}

To reproduce use the following code and zoom to Years level:
this.radDateTimePicker1.Culture = new System.Globalization.CultureInfo("ps-AF");
radDateTimePicker1.DateTimePickerElement.Calendar.HeaderNavigationMode = Telerik.WinControls.UI.HeaderNavigationMode.Zoom;

Workaround: override the ProcessCmdKey method of the form and activate the desired control:
 protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
        {
            if (keyData== Keys.Tab)
            {
                this.ActiveControl = this.radPopupEditor2.PopupEditorElement.TextBoxElement.TextBoxItem.HostedControl;
                return true;
            }
            return base.ProcessCmdKey(ref msg, keyData);
        }

IMPORTANT!!! Tab key should navigate to the next control even if the popup is opened.

To reproduce:
- Use the following format:
radDateTimePicker1.Format = DateTimePickerFormat.Custom;
radDateTimePicker1.CustomFormat = "MM/dd/yyyy";

- Clear the date and try to enter 01/01/2017 (see attched video) 

Workaround:
 radDateTimePicker1.NullDate = DateTime.MinValue.AddYears(1);

Please refer to the attached sample project and attached gif file which illustrates the desired behavior when RadForm1 is run. If you run RadForm2 which uses RadDropDownList, the binding doesn't work as expected.

Workaround:
this.radDropDownList1.SelectedIndexChanged += RadDropDownList1_SelectedIndexChanged;
this.radDropDownList1.DisplayMember = "Naziv";
this.radDropDownList1.ValueMember = "Id";
this.radDropDownList1.DataSource = bs;

private void RadDropDownList1_SelectedIndexChanged(object sender, 
    Telerik.WinControls.UI.Data.PositionChangedEventArgs e)
{
    if (e.Position > -1)
    {
        Roditelj parent = this.radDropDownList1.SelectedItem.DataBoundItem as Roditelj;
        this.radDropDownList2.DataSource = null;
        this.radDropDownList2.DisplayMember = "Naziv";
        this.radDropDownList2.ValueMember = "Id";
        this.radDropDownList2.DataSource = parent.Djeca;
    } 
}

Please refer to the attached sample project and try to open the form's designer. If you comment  [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)] for the EditarTextBox property (typeof(RadTextBox)), clean and rebuild, the designer is opened as expected.

Workaround: use RadTextBoxControl.