My current program reads in an existing .xlsx that contains a few cells with values that look like this (this was made in excel and I haven't created the structure with JavaScript in any way):

{ richText:
   [ { font:
        { bold: true,
          size: 10,
          color: { theme: 1 },
          name: 'Arial',
          family: 2 },
       text: '(j) ' },
     { font: { size: 10, color: { theme: 1 }, name: 'Arial', family: 2 },
       text: 'blah blah blah ' },
     { font:
        { bold: true,
          underline: true,
          size: 10,
          color: { theme: 1 },
          name: 'Arial',
          family: 2 },
       text: 'blah blah' },
     { font: { size: 10, color: { theme: 1 }, name: 'Arial', family: 2 },
       text: ' more blah blah blah \r\n' },
     { font:
        { bold: true,
          size: 10,
          color: { theme: 4 },
          name: 'Arial',
          family: 2 },
       text: '\r\nReference: numbers, blah blah blah' } ] }

The problem is when I write the .xlsx back into a file using workbook.xlsx.writeFile and open in Excel the file is prompted to be repaired, clearing only the cells with rich text, and I get an error (in Excel) of:
Repaired Records: String properties from /xl/sharedStrings.xml part (Strings)
Removed Records: Named range from /xl/workbook.xml part (Workbook)

A temporary solution I found was to just take the cell.value and set it equal to the cell.text which nukes the formatting while keeping the text, and everything works fine, but I was wondering if there was something wrong with the way rich text is being written back into a new file?

Thanks for any help or insight.