Completed
Last Updated: 26 Aug 2026 12:27 by ADMIN
Release 2026.3.826 (2026 Q3)
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;_-* "-"??_-;_-@_-
Completed
Last Updated: 26 Aug 2026 12:27 by ADMIN
Release 2026.3.826 (2026 Q3)
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
Completed
Last Updated: 13 Aug 2026 09:40 by ADMIN
Release Telerik UI for WPF 2026.3.812 (Q3 2026)
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:
var layer = ((NormalWorksheetEditorPresenter)radSpreadsheet.ActiveWorksheetEditor.ActivePresenter).UILayers.GetByName(WorksheetPredefinedUILayers.CellInput);
CellInputUILayer cellInputUILayer = (CellInputUILayer)layer;
cellInputUILayer.ApplyChange();
Completed
Last Updated: 13 Aug 2026 09:40 by ADMIN
Release Telerik UI for WPF 2026.3.812 (Q3 2026)
Value of a cell is visualized outside of the cell boundaries, or the value is clipped and partially visible, when the cell is updated (from code-behind), while being in an inactive worksheet, and is referenced by another cell from the active sheet.

Workaround: get a value of some cell in the active sheet and set it again to the same cell.

The issue is reproducible after the official release of Q1 2015.
Completed
Last Updated: 13 Aug 2026 09:40 by ADMIN
Release Telerik UI for WPF 2026.3.812 (Q3 2026)
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.
Completed
Last Updated: 13 Aug 2026 09:40 by ADMIN
Release Telerik UI for WPF 2026.3.812 (Q3 2026)

For the German language translations, the following resource keys are translated into Dutch instead:

  • Spreadsheet_PrintPreview_FitSheetOnOnePage
  • Spreadsheet_PrintPreview_FitSheetOnOnePage_Description
  • Spreadsheet_PrintPreview_FitColumnsOnOnePage
  • Spreadsheet_PrintPreview_FitColumnsOnOnePage_Description
  • Spreadsheet_PrintPreview_FitRowsOnOnePage
  • Spreadsheet_PrintPreview_FitRowsOnOnePage_Description
Completed
Last Updated: 13 Aug 2026 09:39 by ADMIN
Release 2026.2.624 (2026 Q2)
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;
    }
}
Completed
Last Updated: 02 Jun 2026 09:39 by ADMIN
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.
Completed
Last Updated: 20 May 2026 11:37 by ADMIN
Release 2026.2.520 (2026 Q2)

The label of the field that allows you to set the ScreenTip in the Hyperlink dialog is not vertically centered to the associated textbox visual. This reproduces in the Windows11 theme.

To work this around, get the TextBlock element in the Hyperlink dialog and set its VerticalAlignment property to Center.

private void RadSpreadsheet_Loaded(object sender, RoutedEventArgs e)
{
    var hyperlinkDialog = this.spreadsheet.ActiveWorksheetEditor.Dialogs.HyperlinkDialog as HyperlinkDialogContent;
    hyperlinkDialog.Loaded += HyperlinkDialog_Loaded;
}

private void HyperlinkDialog_Loaded(object sender, RoutedEventArgs e)
{
    var dialog = (HyperlinkDialogContent)sender;
    var screenTipLocalizedText = LocalizationManager.Manager.GetStringOverride("Spreadsheet_InsertHyperlinkDialog_ScreenTip");
    var screenTipTb = dialog.ChildrenOfType<TextBlock>().FirstOrDefault(x => x.Text == screenTipLocalizedText);
    if (screenTipTb != null)
    {
        screenTipTb.VerticalAlignment = VerticalAlignment.Center;
    }            
}

Completed
Last Updated: 20 May 2026 11:37 by ADMIN
Release 2026.2.520 (2026 Q2)
Currently, the headers of the menu items in the context menu are hardcoded. Add localization support so they change based on the applied culture.
Completed
Last Updated: 14 May 2026 16:33 by ADMIN
Release 2026.2.514 (2026 Q2)
#.##0,00;-#.##0,00;;@ does not work in RadSpreadsheet. It should suppress visualizing of ) values.

Workaround: #.##0,00;-#.##0,00; ;@ works fine (there is ' ' [space] set for the zero values).
Completed
Last Updated: 14 May 2026 16:33 by ADMIN
Release 2026.2.514 (2026 Q2)
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
Completed
Last Updated: 14 May 2026 16:33 by ADMIN
Release 2026.2.514 (2026 Q2)
Steps to reproduce:
- Open RadSpreadsheet
 -Put 1 in B2 and B6
 -Put 0 in B3, B4, B5
 -Add filtering on columns A and B
 -Filter on column B to have only rows with 1. The rows 3 to 5 will be hidden.
 -Paste "1234" as cell selection in the Range A2:A6 
 Note: It is important to enter 1234 in another cell, make a cell selection and then paste it
 -Remove the filter

Expected: "1234" in pasted in cells A2 and A6 only.
Actual: "1234" in pasted in cells A2, A3, A4, A5, A6.
Completed
Last Updated: 21 Apr 2026 10:40 by ADMIN
Release Telerik UI for WPF 2026.1.415
Selecting a column with two or more merged cells, selects not only the selected column but the rest of columns that the merged cells are from. The behavior when working with rows is analogical.
Completed
Last Updated: 15 Apr 2026 07:43 by ADMIN
Release Telerik UI for WPF 2026.1.415
Currently, if you have a cell that merges into multiple columns, when you click on the column header, this will select also the adjacent columns where the merged cell extends. Add an option to disable this functionality and select only the cells in the clicked column.
Completed
Last Updated: 11 Feb 2026 09:14 by ADMIN
Release 2026.1.211 (2026 Q1)

The fill selection stops working, after a filtering is applied and the currently selected cell is filtered out (it gets hidden). This prevents from displaying the fill selection cross displayed when you hover the bottom right corner of a selected cell. Any further changes in the selection doesn't re-enable the selection fill feature.

To work this around, you can set the IsEnabled property of the FillSelection on selection changed.

private RadWorksheetEditor activeWorksheetEditor;

public MainWindow()
{
  InitializeComponent();

  this.spreadsheet.ActiveSheetEditorChanged += (s, e) =>
  {
 if (activeWorksheetEditor != null)
 {
 activeWorksheetEditor.Selection.SelectionChanged -= Selection_SelectionChanged;
 }

 activeWorksheetEditor = this.spreadsheet.ActiveWorksheetEditor;
 activeWorksheetEditor.Selection.SelectionChanged += Selection_SelectionChanged;
  };
}

private void Selection_SelectionChanged(object? sender, EventArgs e)
{
  this.spreadsheet.ActiveWorksheetEditor.Selection.FillSelection.IsEnabled = true;
}

Completed
Last Updated: 11 Feb 2026 09:14 by ADMIN
Release 2026.1.211 (2026 Q1)
Multiple rows are not selected in FindAll (Ctrl+F) on the Spreadsheet.
Completed
Last Updated: 11 Nov 2025 08:11 by ADMIN
Release Telerik UI for WPF 2025.4.1111 (2025 Q4)
When selecting multiple cells, clicking on the current active cell (which is selected) does not clear its selection but moves the active cell to one of the other cells from the selected range.
Completed
Last Updated: 11 Nov 2025 08:11 by ADMIN
Release Telerik UI for WPF 2025.4.1111 (2025 Q4)
Data validation dialog buttons should respond to the Enter or Esc keys (Retry, Cancel).
Completed
Last Updated: 20 Aug 2025 15:23 by ADMIN
Release 2025.3.812 (2025 Q3)
When selecting multiple cells while holding the CTRL key, a selected cell cannot be excluded from the selection when clicking on it.
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