java.lang.NullPointerException
        at com.sun.org.apache.xerces.internal.parsers.AbstractDOMParser.startElement(AbstractDOMParser.java:1029)
        at com.sun.org.apache.xerces.internal.impl.dtd.XMLDTDValidator.startElement(XMLDTDValidator.java:767)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1357)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$ContentDriver.scanRootElementHook(XMLDocumentScannerImpl.java:1289)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:3084)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:912)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:645)
        at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:508)
        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:807)
        at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737)
        at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:107)
        at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:225)
        at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:283)
        at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:124)
        at twitter4j.http.Response.<init>(Response.java:45)
        at twitter4j.http.HttpClient.httpRequest(HttpClient.java:122)
        at twitter4j.http.HttpClient.post(HttpClient.java:61)
        at twitter4j.Twitter.update(Twitter.java:242)
        at twitter4j.AsyncTwitter$15.invoke(AsyncTwitter.java:208)
        at twitter4j.AsyncTwitter$AsyncTask.run(AsyncTwitter.java:381)
        at twitter4j.ExecuteThread.run(Dispatcher.java:87)