ArgumentNullException is thrown when importing a document containing a rule with no set format.

If I simply import the xls file with the XlsFormatProvider that RadSpreadProcessing offers and then export it either to xls or xlsx format, the following message pops up when opening the document in MS Excel:

The exported XLS or XLSX file with RadSpreadProcessing contains an additional <definedName>: 

<?xml version="1.0" encoding="utf-8"?>
<workbook xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
	<sheets>
		<sheet sheetId="1" name="Sheet1" state="visible" r:id="rId1" />
	</sheets>
	<definedNames>
		<definedName name="Print_Titles" localSheetId="0" hidden="false">Sheet1!$A$1:$IV$3</definedName>
		<definedName name="_xlnm.Print_Area" localSheetId="0" hidden="false">Sheet1!$A:$G</definedName>
		<definedName name="_xlnm.Print_Titles" localSheetId="0" hidden="false">Sheet1!$1:$3</definedName>
	</definedNames>
</workbook>

This will enable printing with the following printing options: 

- Fit Sheet on One Page

- Fit All Columns on One Page

- Fit All Rows on One Page

- Custom automatic scaling


A possible implementation of a similar behavior is to use the PageSize property of WorksheetPageSetup and subtract the corresponding margin values (from the Margins property) from the width to calculate how many columns are fitting in some particular page size with 100% scale factor. 

Available in R2 2018 Official Release version.

Incorrect calculation of UsedCellRange when conditional formatting is applied to a large cell range.

Workaround:

var usedCellRange = workbook.ActiveWorksheet.GetUsedCellRange(
    CellPropertyDefinitions.AllPropertyDefinitions
    .Except(
        CellPropertyDefinitions.AllPropertyDefinitions.Where(p => p.Name == "DataValidationRule" || p.Name == "ConditionalFormatting")));

It would be beneficial for the clients if every cell has this "cached value" even if the formula can't be evaluated for some reason with the SpreadProcessing - no need for recalculation, just reading the value. It should read the last values while the document was being saved at the originator.

Getting a method like "GetCachedValueString ..." , ideal with the same formatting used for the cell and localization, would be helpful. 

Some of the leftmost borders are omitted when exported to PDF.

ArgumentException  at Telerik.Windows.Documents.FormatProviders.OpenXml.Model.Elements.Theme.SystemColorElement.GetColor(IOpenXmlImportContext context)

The problematic value is val="windowText"

Filter Selection dialog appears on the screen. 

Workaround: Open the file with Excel and save it as a new document.