DNG 6.2: Cerating folder in DNG using OSLC

I have been using this code to create the folder in DNG 6.0 but it is not working after we updated to DNG 6.2, getting 500 response code.

String targetProject = "?projectURL=" + webContextUrl + "/process/project-areas/" + projectID;
                String folderCreationFactory = webContextUrl + "/folders" + targetProject;
                // Create the body content
                StringBuffer folderBody = new StringBuffer();
                folderBody
                .append("<rdf:RDF\n")
                .append("xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns%23\"\n")
                .append("xmlns:dcterms=\"http://purl.org/dc/terms/\"\n")
                .append("xmlns:oslc=\"http://open-services.net/ns/core%23\"\n")
                .append("xmlns:nav=\"http://jazz.net/ns/rm/navigation%23\">\n")
                .append("<nav:folder rdf:about=\"\">\n")
                .append("<dcterms:title>" + folderName + "</dcterms:title>\n")
                .append("<nav:parent rdf:resource=\"" + parentfolder + "\"/>").append("</nav:folder>\n")
                .append("</rdf:RDF>");

                final String content = folderBody.toString();
                // Post to the Requirement Factory
                HttpPost post = new HttpPost(folderCreationFactory);
                post.addHeader("Accept", "application/xml");
                post.addHeader("Content-Type", "application/xml");
                post.addHeader("OSLC-Core-Version", "2.0");
                post.setEntity(new StringEntity(content, HTTP.UTF_8));
                HttpResponse sendPostForSecureDocument = HttpUtils.sendPostForSecureDocument(webContextUrl, post, null, null, client.getHttpClient());
                folderLocation = sendPostForSecureDocument.getFirstHeader("Location");
                sendPostForSecureDocument.getEntity().consumeContent();

Can anyone help me to resolve the issue. Thanks  in advance.