Currently, when the user is editing a cell and saves the document without leaving the edit mode first, the current value is not preserved in the saved document.
When pressing the File -> Save button in the ribbon, the Save dialog doesn't appear at all.
Workaround: Manually commit the change before saving. This workaround will also respect data validation:

When a user setups a page and chooses to customize the Header's Odd and Even pages, the tab headers become clipped.

Some of the RadSpreadsheet child controls do not apply the new theme, but stay with office black applied when theme is set on control level.

At the moment when any of the properties are changed, e.g. the frozen panes, the UI is not notified and you have to export and import the file in order for the UI to pick them up. 


Workaround: There are several workarounds:

1. Change the active worksheet and return to the old one

2. Export and import the document

3. Change the workbook of the RadSpreadsheet to a new one, and return the old one after that
4. Freeze the active worksheet using the ActiveWorksheetEditor.FreezePanes() method and freeze all others using the ViewState:
RadWorksheetEditor editor = this.radSpreadsheet.ActiveWorksheetEditor;
editor.FreezePanes(new CellIndex(3,3));
foreach (var worksheet in this.radSpreadsheet.Workbook.Worksheets)
{
    worksheet.ViewState.FreezePanes(5, 5);
}

We should provide an easier API allowing the customers to remove the key bindings or change the commands that they trigger.

Workaround: There is attached a sample showing how all the commands triggered by the key bindings can be disabled.

If plain text is pasted in a cell, and the text is automatically recognizable as date, number, percentage, formula or other format, the text is always converted to the recognized number format.

Instead, the cell's current number format should affect the convertion in the following way:
- If the current format is General -> parse the value with the automatically recognized format, and set the value with the automatically recognized format
- If the current format is Text -> set the value as text, and preserve the current format (Text)
- If the current format is any other format -> try parse the value with the current format
  - Successful -> set the parsed value with the current format
  - Unsuccessful -> parse the value with the automatically recognized format, and set the parsed value with the current format.

As a result, strings which are recognizable as dates, for example, are pasted as their numeric representation instead of with their Date formatting. Also it's not possible to paste something as plain text. 

Workaround: for always pasting plain text: Create custom Paste button and executes the following code:
this.radSpreadsheet.ActiveWorksheetEditor.Selection.Cells.SetValueAsText(Clipboard.GetText());

When setting the following strings as cell value, they are recognized as dates. In industry standard applications like MS Excel and OpenOffice, they are recognized as strings:
- "12 3456" in bg-BG, fr-FR, ru-RU, sv-FI, en-US
- "12.3456" in de-DE
- "1 23" in en-US
- "2013/5" in en-US
- "3000-03" in en-US

When RadSpreadsheet is placed inside a data template and the Workbook property is bound, the binding fails. 

In the Convert() method of the debug converter, the proper value is set. However, an empty workbook is displayed in the view.

The overlapping of SelectionFill and SelectionStroke geometries may be seen in the attached screenshot. This scenario may be reproduced with the following RadSpreadsheet instance:

<telerik:RadSpreadsheet SelectionStroke="Red" SelectionStrokeThickness="10" FillHandleSelectionStroke="Green" SelectionFill="#550000FF" />

The visualization and scrolling of documents containing many merged cells (e.g. 1000) is very slow. The control becomes almost unusable when the number increases.

Workaround: Import the document without using the default command

OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Filter = "All Spreadsheet Files (*.txt, *.csv, *.pdf, *.xlsx)|*.txt;*.csv;*.pdf;*.xlsx|Excel Workbook (*.xlsx)|*.xlsx|CSV (Comma delimited) (*.csv)|*.csv|Text (Tab delimited) (*.txt)|*.txt|All Files (*.*)|*.*";
if (openFileDialog.ShowDialog() == true)
{
    string extension = Path.GetExtension(openFileDialog.SafeFileName);
    using (Stream input = openFileDialog.OpenFile())
    {
        Workbook workbook = WorkbookFormatProvidersManager.Import(extension, input);
        workbook.Name = openFileDialog.SafeFileName; // in the default implementation this is set after applying the document to RadSpreadsheet and triggers the event
       
        this.radSpreadsheet.Workbook = workbook;
    }
}

If a cell starts with number, contains text, and some values are auto-filled using this cell as base, for example with the Fill handle, the wrong Spreadsheet's autofill generator is used, and ordinal numbers are generated. Instead, the last number (if such) should be increased.

For example, if the cell value is "35'5" and the fill handle is used in order the values to next cells to be autofilled, the values are 35th, 36th and etc., instead of the correct ones which are: 35'6, 35'7,...

Steps to reproduce: 

1. Enter in a cell =Today()
2. Show Format Cells dialog and set Custom format "d"

Expected: The value is the day of the month.
Actual: The date is formatted as short date but has to be day of the month.

When a workbook protection is applied, changing the color of a tab in the sheet selector shouldn't be allowed.

Workaround: Remove the Tab Color item from the Items collection of the SheetSelectorContextMenu. 

If the RadSpreadsheet is declared as a child content in the RadBusyIndicator, there isn't any tab selected as active in the SheetSelector.

Workaround: Declare the busy indicator after the RadSpreadsheet not as its child.

For example, instead of:

<telerik:RadBusyIndicator>
    <telerik:RadSpreadsheet x:Name="radSpreadsheet" />
</telerik:RadBusyIndicator>

Do:

<Grid>
    <telerik:RadSpreadsheet x:Name="radSpreadsheet" />
    <telerik:RadBusyIndicator />
</Grid>

The default set of WPF UI controls measured in infinity results in the minimal size of the control. RadSpreadsheet should behave the same. This will help users to find out what is happening while debugging.

DataValidationRule is persisted after pasting a cell value which is copied from a cell without DataValidationRule applied. 

For example: Cell A1 has data validation rule applied. The cell A2 doesn't have. The value from cell A2 is copied to cell A1. The result is that cell A1 still has data validation, but it shouldn't.

LocalizableException with text "Format string is not in the correct format.", with inner ArgumentException "Format string is not in the correct format." is thrown. 

Currently the validation doesn't allow number format string starting with date or time formatting to have more that one section (for negative and zero numbers). Excel allows this type of number formats and if you set format like dd/mm/yyyy;[RED](#.##0); the positive numbers are visualized as dates, but negative numbers are visualized as numbers and their fore color is red.

Examples (including the final semicolons):

- ss;

- dd;

- dd/mm/yyyy;;

- mmm-yy;mmm-yy;_-* "-"??_-;_-@_-

When number format ends with N commas, the resulting number should be divided to 1000 N times. Instead, such commas are ignored. 

For example, if the format is #.0,, and the value of the cell is 12,200,000, the number should be displayed as 12.200.0

Images inserted in RadSpreadsheet are resized when the active sheet is changed. The set size is very small, making them almost invisible.

Workaround: Remove the two RadNumericUpDowns in the Picture contextual tab in the ribbon UI. They can be recognized by their bindings, to SetShapeWidth.SelectedValue and SetShapeHeight.SelectedValue respectively.

Steps to reproduce:
- Open RadSpreadsheet with the default Ribbon UI present.
- Insert image using the button in the Ribbon -> Illustrations -> Pictures.
- Add new sheet using the Sheet Selector (+) button, or change the sheet to another sheet
- Return to the initial sheet.

Expected: The image retains its original size.
Actual: The image size is changed to very small one.