The table border styles are not imported correctly with a specific document.

Workaropund:

RtfFormatProvider provider = new RtfFormatProvider();
RadFlowDocument document = provider.Import(File.ReadAllText(@"..\..\test.rtf"));
 
PdfFormatProvider pdfProvider = new PdfFormatProvider();
var tables = document.EnumerateChildrenOfType<Table>();

foreach (var table in tables)
{
    table.Borders = new TableBorders(new Border(BorderStyle.None));
}


using (FileStream stream = File.OpenWrite(@"..\..\result.pdf"))
{
    pdfProvider.Export(document, stream);
}

Import of Tables with border style needs improvements. Currently, it takes multiple seconds to import table with 100x6 cells no matter if the border style is defined globally or locally. This may be seen when importing the attached files "table with borders.html" and "table single border style.html". Importing the same table without borders is achieved in less than a second which may be seen with the attached "table without borders.html".

If a document has runs with font size larger than the one set in the style of the paragraphs and this document is exported to HTML, the resulting paragraphs overlap.

This is only reproducible when the Run contains an empty string. If the paragraph is empty or the Run contains a space, everything is working correctly.

Workaround: Remove all empty runs from the document.

For example:
Renaming a sheet named "Sheet1" to "Sheet 1", should update formulas references to it to 'Sheet 1!' (notice single quotes), which it does not. The formula =SUM(Sheet1!A2:C2) changes to the invalid expression =SUM(Sheet 1!A2:C2). This breaks formulas referencing that sheet.

Workaround:
Iterate all cells with formulas in the workbook and add single quotes to the beginning and end of sheet name reference. The attached project changes the name of Sheet1 and then fixes all formula references to it by enclosing its name in single quotes.