To reproduce:
- Add two child templates to a grid.
- Add summary rows to both of them 
- Change the value of the child template.

Workaround:
- Clear and add back the summary rows when a value in the child template is changed. 

To reproduce:
- Set the cell's BackColor in an entire column.
- Set the cell's Forecolor in another column. 
- Change the grid size to the columns are hidden and then shown again.

Workaround:
Change similar properties for all the cells where the Style property is used or use CellFormatting.

To reproduce:

GridViewMultiComboBoxColumn supplierColumn = new GridViewMultiComboBoxColumn();
supplierColumn.SyncSelectionWithText = true;
supplierColumn.Name = "SupplierColumn";
supplierColumn.HeaderText = "Supplier";
supplierColumn.DropDownStyle = Telerik.WinControls.RadDropDownStyle.DropDown;
supplierColumn.AutoCompleteMode = AutoCompleteMode.Append;
supplierColumn.DataSource = this.suppliersBindingSource;
supplierColumn.ValueMember = "SupplierID";
supplierColumn.DisplayMember = "ContactName";
supplierColumn.FieldName = "SupplierID";
supplierColumn.Width = 200;
this.radGridView1.Columns.Add(supplierColumn);

Select the new row and try to enter some text that is not valid and press Enter. You will notice the new row is added with the last valid auto-completed value.

Workaround: cancel the UserAddingRow event if the entered text is not valid.

To reproduce:
- Enter a value in the search row (make sure you will have several results)
- Enter a letter in the filtering row. The filetring row will lose the focus.

Workaround:
public class MyGridViewSearchRowInfo : GridViewSearchRowInfo
{
    public MyGridViewSearchRowInfo(GridViewInfo viewInfo) : base(viewInfo)
    {
    }

    public override void SelectNextSearchResult()
    {
        GridViewSystemRowInfo systemRow = this.ViewTemplate.MasterTemplate.CurrentRow as GridViewSystemRowInfo;

        if (systemRow != null && this.ViewTemplate.MasterTemplate.Owner.EditorManager.IsInEditMode)
        {
            return;
        }
        base.SelectNextSearchResult();
    }
}

//change the default row like this
void radGridView1_CreateRowInfo(object sender, GridViewCreateRowInfoEventArgs e)
{
    if (e.RowInfo is GridViewSearchRowInfo)
    {
        e.RowInfo = new MyGridViewSearchRowInfo(e.ViewInfo);
    }
}

To reproduce:
- Add grid with several columns and set their AllowResize property to false.
- Set the FitWidthMode to FitPageWidth.
- Print the grid and you will notice that some of the columns are cut off.
 
Workaround:
- Set the AllowResize property to true before printing.

To reproduce :
- Set conditional formatting for all grid cells.
- Iterate all grid cells and set their value.

Workaround:
Use Begin/End update block.

Please refer to the attached screenshot.

Workaround: either select the RadGridView node in the Property Builder, or use the VS design time or control Smart Tag to set DataSource

To reproduce:
Me.RadGridView1.MultiSelect = True

Private Sub RadGridView1_CellFormatting(sender As Object, e As Telerik.WinControls.UI.CellFormattingEventArgs) _
Handles RadGridView1.CellFormatting
    If e.Row.IsSelected Then
        e.CellElement.BackColor = Color.LimeGreen
        e.CellElement.DrawFill = True
        e.CellElement.GradientStyle = Telerik.WinControls.GradientStyles.Solid
    Else
        e.CellElement.ResetValue(LightVisualElement.BackColorProperty, ValueResetFlags.Local)
        e.CellElement.ResetValue(LightVisualElement.DrawFillProperty, ValueResetFlags.Local)
        e.CellElement.ResetValue(LightVisualElement.GradientStyleProperty, ValueResetFlags.Local)
    End If
End Sub

Step 1: Select a few rows with the mouse click in combination with the CTRL key.
Step 2: The rows are selected correctly and the desired green back color is applied. Release the CTRL Key.
Step 3: Click with the mouse on a different row in the grid.

Result: All previously selected rows but the last current row keep the green back color.

Workaround:

Sub New()
    InitializeComponent()
 
    Me.RadGridView1.MultiSelect = True
    AddHandler Me.RadGridView1.SelectionChanging, AddressOf SelectionChanging
    AddHandler Me.RadGridView1.SelectionChanged, AddressOf SelectionChanged
 
End Sub
 
Private Sub RadGridView1_CellFormatting(sender As Object, e As Telerik.WinControls.UI.CellFormattingEventArgs) _
Handles RadGridView1.CellFormatting
    e.CellElement.DrawFill = True
    e.CellElement.GradientStyle = Telerik.WinControls.GradientStyles.Solid
    If e.Row.IsSelected Then
        e.CellElement.BackColor = Color.LimeGreen
    Else
        e.CellElement.BackColor = Color.Yellow
    End If
End Sub
Private Sub SelectionChanged(sender As Object, e As EventArgs)
    For Each r As GridViewRowInfo In selectedRows
        r.InvalidateRow()
    Next
    selectedRows.Clear()
End Sub
 
Dim selectedRows As New List(Of GridViewRowInfo)
Private Sub SelectionChanging(sender As Object, e As GridViewSelectionCancelEventArgs)
    For Each r As GridViewRowInfo In Me.RadGridView1.SelectedRows
        selectedRows.Add(r)
    Next
End Sub

To reproduce:
private RadGridView radGridView1;

public Form1()
{
    InitializeComponent();
    radGridView1 = new RadGridView() { Dock = DockStyle.Fill };
    Controls.Add(radGridView1);

    List<Item> items = new List<Item>();
    for (int i = 0; i < 10; i++)
    {
        items.Add(new Item(i, "Item" + i, DateTime.Now.AddDays(i)));
    }
    radGridView1.AutoGenerateColumns = true;
    this.radGridView1.DataSource = items;
    this.radGridView1.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;
    this.radGridView1.EnableFiltering = true;

    this.radGridView1.CustomFiltering += radGridView1_CustomFiltering;
    radGridView1.EnableCustomFiltering = true;
}

void radGridView1_CustomFiltering(object sender, GridViewCustomFilteringEventArgs e)
{
    e.Handled = false;
    e.Visible = true;

    var item = (Item)e.Row.DataBoundItem;

    if (item == null)
        return;

    if (item.Name.EndsWith("Item"))
    {
        e.Handled = true;
        e.Visible = false;
    }
}

public class Item
{
    public int Id { get; set; }

    public string Name { get; set; }

    public Nullable<DateTime> Date { get; set; }

    public Item(int id, string name, Nullable<DateTime> date)
    {
        this.Id = id;
        this.Name = name;
        this.Date = date;
    }
}


Workaround:

private void radGridView1_CellEndEdit(object sender, GridViewCellEventArgs e)
{
    this.radGridView1.MasterTemplate.Refresh();
}

Workaround: set up the templates from code, http://www.telerik.com/help/winforms/gridview-overview.html

Use the following help article to set up the hierarchy >> http://www.telerik.com/help/winforms/gridview-hierarchical-grid-self-referencing-hierarchy.html

Please refer to the attached gif files illustrating the behavior in Q1 SP and Q2.

Workaround:

public Form1()
{
    InitializeComponent();
    this.radGridView1.CreateCell += radGridView1_CreateCell;
    GridViewCheckBoxColumn checkBoxColumn = new GridViewCheckBoxColumn("CheckBoxColumn");
    checkBoxColumn.EnableHeaderCheckBox = false;
    checkBoxColumn.ThreeState = true;
    checkBoxColumn.EditMode = EditMode.OnValueChange;
   
    radGridView1.MasterTemplate.Columns.Add(checkBoxColumn);
    radGridView1.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;
    for (int i = 0; i < 20; i++)
    {
        this.radGridView1.Rows.Add(false);
    }
}

private void radGridView1_CreateCell(object sender, GridViewCreateCellEventArgs e)
{
    if (e.CellType == typeof(GridCheckBoxHeaderCellElement))
    {
        CustomGridCheckBoxHeaderCellElement headerCell = new CustomGridCheckBoxHeaderCellElement(e.Column, e.Row);
        e.CellElement = headerCell;
    }
}

public class CustomGridCheckBoxHeaderCellElement : GridHeaderCellElement
{
    public CustomGridCheckBoxHeaderCellElement(GridViewColumn column, GridRowElement row) : base(column, row)
    {
    }

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

    RadCheckBoxElement cb = new RadCheckBoxElement();

    protected override void CreateChildElements()
    {
        base.CreateChildElements();
        this.Children.Add(cb);
        cb.IsThreeState = true;
        cb.ToggleState = Telerik.WinControls.Enumerations.ToggleState.Off;
        cb.ToggleStateChanged += CheckBox_ToggleStateChanged;
    }

    bool boolValue = false;

    public override void SetContent()
    {
        base.SetContent();

        if (!flag)
        {
            bool atLeastOneTrue = false;
            bool atLeastOneFalse = false;
            foreach (GridViewRowInfo r in this.GridViewElement.Template.Rows)
            {
                if (r.Cells[0].Value != null)
                {
                    if (atLeastOneTrue && atLeastOneFalse)
                    {
                        break;
                    }

                    boolValue = (bool)r.Cells[0].Value;
                    if (boolValue)
                    {
                        atLeastOneTrue = true;
                    }
                    else
                    {
                        atLeastOneFalse = true;
                    }
                }
                else
                {
                    atLeastOneFalse = true;
                }
            }

            if (atLeastOneFalse && atLeastOneTrue)
            {
                cb.ToggleStateChanged -= CheckBox_ToggleStateChanged;
                cb.ToggleState = Telerik.WinControls.Enumerations.ToggleState.Indeterminate;
                cb.ToggleStateChanged += CheckBox_ToggleStateChanged;
            }
            else if (atLeastOneFalse == true)
            {
                cb.ToggleStateChanged -= CheckBox_ToggleStateChanged;
                cb.ToggleState = Telerik.WinControls.Enumerations.ToggleState.Off;
                cb.ToggleStateChanged += CheckBox_ToggleStateChanged;
            }
            else if (atLeastOneTrue == true)
            {
                cb.ToggleStateChanged -= CheckBox_ToggleStateChanged;
                cb.ToggleState = Telerik.WinControls.Enumerations.ToggleState.On;
                cb.ToggleStateChanged += CheckBox_ToggleStateChanged;
            }
        }
    }

    bool flag = false;

    private void CheckBox_ToggleStateChanged(object sender, StateChangedEventArgs args)
    {
        cb.ToggleStateChanged -= CheckBox_ToggleStateChanged;
        flag = true;
        if (args.ToggleState == Telerik.WinControls.Enumerations.ToggleState.Indeterminate)
        {
            cb.ToggleState = Telerik.WinControls.Enumerations.ToggleState.Off;                   
        }
        ToggleStateForChildRows(args.ToggleState, this.GridControl);
        flag = false;
        cb.ToggleStateChanged += CheckBox_ToggleStateChanged;
    }

    private void ToggleStateForChildRows(Telerik.WinControls.Enumerations.ToggleState toggleState, RadGridView radGridView)
    {
        foreach (GridViewRowInfo r in radGridView.Rows)
        {
            r.Cells[0].Value = toggleState == Telerik.WinControls.Enumerations.ToggleState.On;
        }
    }
}

1. Use the following code snippet:
public Form1()
{
    InitializeComponent();

    this.radGridView1.MasterTemplate.AutoSizeColumnsMode = Telerik.WinControls.UI.GridViewAutoSizeColumnsMode.Fill;
    this.radGridView1.MasterTemplate.EnableAlternatingRowColor = true;
    this.radGridView1.MasterTemplate.EnableFiltering = true;
    this.radGridView1.MasterTemplate.MultiSelect = true;

    for (int i = 0; i < 3; i++)
    {
        this.radGridView1.Columns.Add("Col"+i);
    }
    radGridView1.Rows.Add("test1", "test1", "test1");
    radGridView1.Rows.Add("test2", "test2", "test2");
    radGridView1.Rows.Add("test3", "test3", "test3");
    radGridView1.Rows.Add("test4", "test4", "test4");
    radGridView1.Rows.Add("test5", "test5", "test5");
}

2. Quickly click around  the cells a few times, making sure to drag your mouse a bit  to select a few rows on some of the clicks.
Then quickly click the filter. (sometimes it takes a few tries)

Workaround: use custom GridFilterRowBehavior

            BaseGridBehavior gridBehavior = radGridView1.GridBehavior as BaseGridBehavior;
            gridBehavior.UnregisterBehavior(typeof(GridViewFilteringRowInfo));
            gridBehavior.RegisterBehavior(typeof(GridViewFilteringRowInfo), new CustomGridFilterRowBehavior());

public class CustomGridFilterRowBehavior : GridFilterRowBehavior
{
    protected override bool ProcessMouseSelection(Point mousePosition, GridCellElement currentCell)
    { 
        return false;
    }
}

To reproduce:
- Add GridViewDateTimeColumn.
- Set the editor properties:
private void radGridView_VehicleAbsenceTime_CellEditorInitialized(object sender, GridViewCellEventArgs e)
{
    RadDateTimeEditor lEditor = radGridView_VehicleAbsenceTime.ActiveEditor as RadDateTimeEditor;
    if (lEditor != null)
    {
        RadDateTimeEditorElement editorElement = (RadDateTimeEditorElement)lEditor.EditorElement;
        editorElement.Format = DateTimePickerFormat.Custom;
        editorElement.CustomFormat = "dd.MM.yyyy HH:mm";
        editorElement.ShowUpDown = true;
    }
}
- Start the application scroll to the bottom and start editing.

To reproduce:
GridViewSpreadExport spreadExporter = new GridViewSpreadExport(this.radGridView1);
spreadExporter.RunExport(@"C:\exportedFile.xlsx");

Workaround:
GridViewSpreadExport spreadExporter = new GridViewSpreadExport(this.radGridView1);
spreadExporter.RunExport(@"C:\exportedFile.xlsx", new SpreadExportRenderer());

Alternatively you can set the Copy Local property of the TelerikExport assembly to true.

Workaround: set the theme with ThemeResolutionService.ApplicationThemeName = "MyThemeName