To reproduce:

public Form1()
{
    InitializeComponent();
    this.radPropertyGrid1.SelectedObject = this;

    this.radPropertyGrid1.ContextMenuOpening += radPropertyGrid1_ContextMenuOpening;
}

private void radPropertyGrid1_ContextMenuOpening(object sender, Telerik.WinControls.UI.PropertyGridContextMenuOpeningEventArgs e)
{
    foreach (RadItem item in e.Menu.Items)
    {
        if (item.Text == "Sort")
        {
            item.Visibility = ElementVisibility.Collapsed;
            item.PropertyChanged += item_PropertyChanged;
        }
    }
}

Workaround:
private void radPropertyGrid1_ContextMenuOpening(object sender, Telerik.WinControls.UI.PropertyGridContextMenuOpeningEventArgs e)
{
    RadItem item = null;
    for (int i = 0; i < e.Menu.Items.Count; i++)
    {
        item = e.Menu.Items[i];
        if (item.Text=="Sort")
        {
            e.Menu.Items.Remove(item);
        }
    } 
}

To reproduce: 

CultureInfo culture = new CultureInfo("en-US");
culture.DateTimeFormat.FirstDayOfWeek = DayOfWeek.Monday;
culture.DateTimeFormat.CalendarWeekRule = CalendarWeekRule.FirstFourDayWeek;
this.radCalendar1.ShowRowHeaders = true;
this.radCalendar1.Culture = culture;

To reproduce:

1. Add a RadGridView with a GridViewMultiComboBoxColumn. Enable the auto filter functionality for this column and add an appropriate FilterDescriptor to the RadMultiColumnComboBoxElement.
2. Using the keyboard arrows only (no mouse), navigate to the GridViewMultiComboBoxColumn.
3. Type "ba" by using the keyboard. The "b" is lost and only the "a" gets to the filter. I expect the filter to show "ba".

Workaround: use custom row behavior

public Form1()
{
    InitializeComponent();
    //register the custom row  behavior
    BaseGridBehavior gridBehavior = radGridView1.GridBehavior as BaseGridBehavior;
    gridBehavior.UnregisterBehavior(typeof(GridViewDataRowInfo));
    gridBehavior.RegisterBehavior(typeof(GridViewDataRowInfo), new CustomGridDataRowBehavior());
}

public class CustomGridDataRowBehavior : GridDataRowBehavior
{
    protected override bool ProcessAlphaNumericKey(KeyPressEventArgs keys)
    {
        bool result = base.ProcessAlphaNumericKey(keys);
        if (this.IsInEditMode &&
            (this.BeginEditMode == RadGridViewBeginEditMode.BeginEditOnKeystroke ||
             this.BeginEditMode == RadGridViewBeginEditMode.BeginEditOnKeystrokeOrF2))
        {
            if (this.GridViewElement.ActiveEditor is RadMultiColumnComboBoxElement)
            {
                this.GridViewElement.ActiveEditor.Value = keys.KeyChar;
                if (this.GridViewElement.IsInEditMode)
                {
                    RadMultiColumnComboBoxElement mccb = (RadMultiColumnComboBoxElement)this.GridViewElement.ActiveEditor;
                    RadTextBoxItem textBoxItem = mccb.TextBoxElement.TextBoxItem;
                    textBoxItem.Clear();
                    textBoxItem.Text =  keys.KeyChar.ToString();
                    textBoxItem.SelectionStart = 1;
                    textBoxItem.SelectionLength = 0;
                }

                return true;
            }
        }
        return result;
    }
}

Expose a way to disable the Spell Checking Complete dialog:

When RadPanel is set to AutoSize, it should update its size automatically when changing the visibility of some control inside it.

Workaround:
 public class CustomRadPanel : RadPanel
    {
        public override string ThemeClassName
        {
            get
            {
                return typeof(RadPanel).FullName;
            }
            set
            {
                base.ThemeClassName = value;
            }
        }

        protected override void OnLayout(LayoutEventArgs e)
        {
            base.OnLayout(e);
            int maxHeight = 0;
            foreach (Control control in this.Controls)
            {
                if (control.Visible)
                {
                    maxHeight = Math.Max(control.Height, maxHeight);
                }
            }
            this.AutoSize = false;
            this.Height = maxHeight;
        }
    }

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.

Description: LostFocus event for the RadDropDownList fires after PopupClosed and before SelectedIndexChanging events no matter that the user have not leave the control yet.

To reproduce:
- add a RadDropDownList with items
- subscribe for the LostFocus event
- open the drop down list and close it: the LostFocus event fires

Workaround:
Use RadDropDownList Leave event:

this.radDropDownList1.Leave += radDropDownList1_Leave;

To reproduce:
- Add pie chart and drop down list with some items to a form.
- Then use the following code:

Private Sub RadForm1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Dim series As New PieSeries

    series.DataPoints.Add(New PieDataPoint(50, "test"))
    series.DataPoints.Add(New PieDataPoint(50, "test2"))

    series.ShowLabels = True

    RadChartView1.Series.Add(series)

    TryCast(RadChartView1.Series(0).Children(0), PiePointElement).BackColor = Color.Red
    TryCast(RadChartView1.Series(0).Children(1), PiePointElement).BackColor = Color.Blue
End Sub

Private Sub RadChartView1_LabelFormatting(sender As Object, e As ChartViewLabelFormattingEventArgs) Handles RadChartView1.LabelFormatting
    e.LabelElement.Shape = New OfficeShape(True)
End Sub

Workaround:
e.LabelElement.SuspendPropertyNotifications()
e.LabelElement.Shape = New OfficeShape(True)
e.LabelElement.ResumePropertyNotifications()

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

To reproduce:
- Add three line series and only set their point size.
- At runtime remove the second series.
- The points color is not updated corectly.

Workaround
- Set colors in code like this:
lineSerie1.BorderColor = Color.Red;
lineSerie1.BackColor = Color.Red;

lineSerie2.BackColor = Color.Green;
lineSerie2.BorderColor = Color.Green;

lineSerie3.BackColor = Color.Blue;
lineSerie3.BorderColor = Color.Blue;

Please refer to the attached screenshot.

To reproduce:

public RadForm1()
{
    InitializeComponent();
    
    Font f = new Font("Microsoft Sans Serif", 9.5f);
    this.radDropDownList1.DropDownStyle = Telerik.WinControls.RadDropDownStyle.DropDownList;
    this.radDropDownList1.Font = f;

    this.radDropDownList2.DropDownStyle = Telerik.WinControls.RadDropDownStyle.DropDown;
    this.radDropDownList2.Font = f;
}

Workaround:  If the text is not completely visible in RadDropDownList for a specific font you can increase the minimum height of the RadDropDownList and the DropDownListElement.TextBox.TextBoxItem.TextBoxControl.

public RadForm1()
{
    InitializeComponent();
    this.radDropDownList1.MinimumSize = new Size(0, 25);
    this.radDropDownList1.DropDownListElement.TextBox.TextBoxItem.TextBoxControl.MinimumSize = new Size(0, 25);
}

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);
}

If you try to style the Right column menu of RadApplicationMenu, your changes will not be persisted and applied to the control.

Workaround: 
FillPrimitive fill = (FillPrimitive)this.radRibbonBar1.RibbonBarElement.ApplicationButtonElement.DropDownMenu.RootElement.Children[0].Children[0].Children[2].Children[0].Children[2].Children[1].Children[0];
fill.BackColor = Color.Orange;
fill.BackColor2 = Color.Red;

Text is clipped on the right when line numbers are hidden and word wrap is disabled.