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.

Through the sorting options, the user can set sort orientation (to sort by rows or by columns) and whether the sort should be case sensitive.

When the VisibleSize property of the spreadsheet control is set (for example new SizeI(10, 10)) and column is selected via its header (click on it), the IsColumnSelection property of the ActiveWorksheetEditor's Selection returns False. This applies also for the IsRowSelection property.

NullReferenceException is thrown when the VisibleSize property of RadSpreadsheet is set more than once on two (or more) adjacent lines. For example:

spreadsheet.VisibleSize = new SizeI(1, 1);
spreadsheet.VisibleSize = new SizeI(5, 5);

To work this around you can increase the time between the settings of the VisibleSize property. For example you can use the ActiveSheetEditorChanged event of RadSpreadsheet and the ActivePresenterChanged event of the ActiveWorksheetEditor, and the UIUpdated event of the ActivePresenter. Each time the VisibleSize is changed, the ActiveWorksheetEditor will be recreated along with its ActivePresenter. You should make sure the second, third, etc. setting of the VisibleSize is executed after the new ActivePresenter is loaded. This can be done in the UIUpdated event.

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.

The SUMIFS function adds all of its arguments that meet multiple criteria.

A list of the supported functions is available at http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/features/formulas/functions

This function can be implemented as a custom function. Check the following resources for more details on how to achieve that:

- http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/features/formulas/custom-functions
- https://github.com/telerik/xaml-sdk/tree/master/Spreadsheet/WPF/CustomFunctions

The exception is thrown when the color for the borders has been previously set using the colors from the predefined palette. The next attempt to set a border color using the ShowMoreColorsDialog leads to error. A message appears to the user saying "Specified cast is not valid".

Implement mechanism for disabling, enabling or changing of the commands of the CellEditor classes, like Copy and Paste.

If a document contains many and complex formulas (with many functions having other functions as arguments) it may take a long time to show in the control.

When the PrintPreview has to show many UIElements at once, the performance is slow.

SUBSTITUTE  - replaces text in a given string by matching.
REPLACE - replaces characters specified by location in a given text string with another text string.

Currently, caching formula results is not supported.

According to the Open XML documentation, the possible max value for this attribute is an unsignedInt or 4294967295.

Enable users to localize the default styles names.

TickLabelPosition is skipped on importing documents containing charts. When the Value axis has both positive and negative values being able to specify tick labels' position makes the chart readable, otherwise, labels are positioned in the middle of the chart. There are four positions - High, Low, NextTo and None.

When importing a document containing a destination that does not refer to a formula an exception is thrown: System.NullReferenceException: 'Object reference not set to an instance of an object.'

Right borders are not rendered correctly when there is no value. 

The data validation error message box has an invalid size when shown multiple times

Implement pasting of images similar to Excel.