Not able to create package using docx4j WordprocessingMLPackage in java

Question

Converting a html file or string through docx4j getting an error while running the code

    public static void convertHtmltoWord2(String html) {

       WordprocessingMLPackage wordMLPackage = WordprocessingMLPackage.createPackage();
                    
        NumberingDefinitionsPart ndp = new NumberingDefinitionsPart();
        wordMLPackage.getMainDocumentPart().addTargetPart(ndp);
        ndp.unmarshalDefaultNumbering();        
                    
        // Convert the HTML, and add it into the empty docx we made
        XHTMLImporterImpl XHTMLImporter = new XHTMLImporterImpl(wordMLPackage);
        
        XHTMLImporter.setHyperlinkStyle("Hyperlink");
        wordMLPackage.getMainDocumentPart().getContent().addAll( 
                XHTMLImporter.convert(html, baseURL) );
    
        wordMLPackage.save(new java.io.File("C:\\Converted_Word.docx") );

}

Below Error:

java.util.NoSuchElementException
at org.docx4j.openpackaging.parts.WordprocessingML.MainDocumentPart.<init>(MainDocumentPart.java:76)
    at org.docx4j.openpackaging.packages.WordprocessingMLPackage.createPackage(WordprocessingMLPackage.java:432)
    at org.docx4j.openpackaging.packages.WordprocessingMLPackage.createPackage(WordprocessingMLPackage.java:421)

Any idea why its not working?