XmlRpcException when I goes to post data

I have a code to post data on word press i.e.-

String username = "xyz";
String password = "xyz";
String xmlRpcUrl = "https://www.arrestcentral.com/xmlrpc.php?";
WordPress wp = new WordPress(username, password, xmlRpcUrl);
Page recentPost = new Page();
String result = wp.newPost(recentPost, true);

These same code was working 2 month but now its not working. Now when I goes to post data is showing an exception i.e.-

[Fatal Error] :2:6: The processing instruction target matching “[xX][mM][lL]” is not allowed.
redstone.xmlrpc.XmlRpcException: The response could not be parsed.
at redstone.xmlrpc.XmlRpcClient.handleResponse(Unknown Source)
at redstone.xmlrpc.XmlRpcClient.endCall(Unknown Source)
at redstone.xmlrpc.XmlRpcClient.invoke(Unknown Source)
at redstone.xmlrpc.XmlRpcProxy.invoke(Unknown Source)
at net.bican.wordpress.$Proxy1.newMediaObject(Unknown Source)
at net.bican.wordpress.Wordpress.newMediaObject(WordPress.java:582)
at WordPressPost.DataWordpressPost.DataPost(DataWordpressPost.java:54)
at arrestcentral.ArrestData.readPdf(ArrestData.java:423)
at arrestcentral.ArrestpdfLink.pdfLink(ArrestpdfLink.java:93)
at arrestcentral.ArrestpdfLink.startPosting(ArrestpdfLink.java:46)
at arrestcentral.ArrestpdfLink.main(ArrestpdfLink.java:128)
Caused by: redstone.xmlrpc.XmlRpcException: A problem occured during parsing
at redstone.xmlrpc.XmlRpcParser.parse(Unknown Source)
… 11 more
Caused by: org.xml.sax.SAXParseException: The processing instruction target matching “[xX][mM][lL]” is not allowed.
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1231)
… 12 more

I am using
xmlrpc-client-1.1
WordPress 3.2.1