Error in parsing the HTML using XMLworkerHelper

Question

I am getting "Invalid nested tag font found, expected closing tag table" when trying to convert one HTML to PDF using iText. Following is the program I am using.

import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.StringReader;

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.Font.FontFamily;
import com.itextpdf.text.pdf.ColumnText;
import com.itextpdf.text.pdf.GrayColor;
import com.itextpdf.text.pdf.PdfPageEventHelper;
import com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.tool.xml.XMLWorkerHelper;


public class HTML2PDF { 
class Watermark extends PdfPageEventHelper{
        //font for watermarking text
        Font font = new Font(FontFamily.HELVETICA, 52, Font.ITALIC, new GrayColor(.75f));
        public void onEndPage(PdfWriter writer, Document document){
            ColumnText.showTextAligned(writer.getDirectContentUnder(), 
                    Element.ALIGN_CENTER, 
                    new Phrase("Watermarking Text", font), 
                    297.5f, 421,-45);//-45 specifies the angle of Watermarking Text
        }
    }

    public void convertHTML2PDF(){
        //Create objects of Document and specify the Page size of a PDF
        Document document = new Document(PageSize.A4);
        try{
            PdfWriter pdfWriter;
            //get the instance of class PdfWriter with the document objects and output path
            pdfWriter = PdfWriter.getInstance(document, new FileOutputStream("/opt/remedy/html2any-cmd-linux/bin/test.pdf"));
            //setting the Watermarking in the PageEvent of PdfWriter
            pdfWriter.setPageEvent(new Watermark());
            document.open();

            String htmlContent = "";
            BufferedReader in = new BufferedReader(new FileReader("/opt/remedy/html2any-cmd-linux/bin/WO00000001004641434460592596_1.html"));
            String temp;
            //read the html files content and stores it in a String variable
            while((temp = in.readLine())!=null){
                htmlContent += temp;
            }
            in.close();
            XMLWorkerHelper xmlWorker = XMLWorkerHelper.getInstance();
            // converts the html into a PDF
            xmlWorker.parseXHtml(pdfWriter, document, new StringReader(htmlContent));
            document.close();

        } 
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
    //main method
    public static void main(String[] args){
        new HTML2PDF().convertHTML2PDF();
    }

}

There are some tags in html which do not need to be closed. Could you suggest how this type of html can be parsed using XMLWorker?