title: Upgrading to Struts 2.3.15 - Convention Plugin cause crash on startup
body: <p>I'm in the process of upgrading my Struts2 installation to 2.3.15. After adding the <code>struts2-convention-plugin-2.3.15.jar</code> my web-app fails to start. The relevant part of the exception listing is;</p>
  
  <pre><code>Caused by: Attribute "order" must be declared for element type "struts". - jar:file:/H:/apache-tomcat-7.0.20/wtpwebapps/FaultmateGenesis-Server/WEB-INF/lib/struts2-convention-plugin-2.3.15.jar!/struts-plugin.xml:29:20
  at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:119)
  at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:1017)
  ... 16 more
  </code></pre>
  
  <p>Anyone got any idea what's going on?</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>The full trace is;</p>
  
  <pre><code>SEVERE: Exception sending context initialized event to listener instance of class org.apache.struts2.dispatcher.ng.listener.StrutsListener
  Unable to load configuration. - jar:file:/H:/apache-tomcat-7.0.20/wtpwebapps/FaultmateGenesis-Server/WEB-INF/lib/struts2-convention-plugin-2.3.15.jar!/struts-plugin.xml:29:20
  at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:502)
  at org.apache.struts2.dispatcher.ng.InitOperations.initDispatcher(InitOperations.java:74)
  at org.apache.struts2.dispatcher.ng.listener.StrutsListener.contextInitialized(StrutsListener.java:46)
  at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4701)
  at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5204)
  at org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5199)
  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
  at java.util.concurrent.FutureTask.run(FutureTask.java:166)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
  at java.lang.Thread.run(Thread.java:722)
   Caused by: Unable to load configuration. - jar:file:/H:/apache-tomcat-7.0.20/wtpwebapps/FaultmateGenesis-Server/WEB-INF/lib/struts2-convention-plugin-2.3.15.jar!/struts-plugin.xml:29:20
  at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:70)
  at org.apache.struts2.dispatcher.Dispatcher.init_PreloadConfiguration(Dispatcher.java:446)
  at org.apache.struts2.dispatcher.Dispatcher.init(Dispatcher.java:490)
  ... 10 more
  Caused by: Unable to load jar:file:/H:/apache-tomcat-7.0.20/wtpwebapps/FaultmateGenesis-Server/WEB-INF/lib/struts2-convention-plugin-2.3.15.jar!/struts-plugin.xml - jar:file:/H:/apache-tomcat-7.0.20/wtpwebapps/FaultmateGenesis-Server/WEB-INF/lib/struts2-convention-plugin-2.3.15.jar!/struts-plugin.xml:29:20
  at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:1022)
  at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadDocuments(XmlConfigurationProvider.java:165)
  at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:132)
  at com.opensymphony.xwork2.config.impl.DefaultConfiguration.reloadContainer(DefaultConfiguration.java:225)
  at com.opensymphony.xwork2.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:67)
  ... 12 more
   Caused by: Attribute "order" must be declared for element type "struts". - jar:file:/H:/apache-tomcat-7.0.20/wtpwebapps/FaultmateGenesis-Server/WEB-INF/lib/struts2-convention-plugin-2.3.15.jar!/struts-plugin.xml:29:20
  at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:119)
  at com.opensymphony.xwork2.config.providers.XmlConfigurationProvider.loadConfigurationFiles(XmlConfigurationProvider.java:1017)
  ... 16 more
   Caused by: org.xml.sax.SAXParseException; systemId: jar:file:/H:/apache-tomcat-7.0.20/wtpwebapps/FaultmateGenesis-Server/WEB-INF/lib/struts2-convention-plugin-2.3.15.jar!/struts-plugin.xml; lineNumber: 29; columnNumber: 20; Attribute "order" must be declared for element type "struts".
  at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
  at org.apache.xerces.util.ErrorHandlerWrapper.error(Unknown Source)
  at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
  at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
  at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
  at org.apache.xerces.impl.dtd.XMLDTDValidator.addDTDDefaultAttrsAndValidate(Unknown Source)
  at org.apache.xerces.impl.dtd.XMLDTDValidator.handleStartElement(Unknown Source)
  at org.apache.xerces.impl.dtd.XMLDTDValidator.startElement(Unknown Source)
  at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
  at org.apache.xerces.impl.XMLNSDocumentScannerImpl$NSContentDispatcher.scanRootElementHook(Unknown Source)
  at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
  at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
  at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
  at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
  at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
  at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
  at org.apache.xerces.jaxp.SAXParserImpl.parse(Unknown Source)
  at com.opensymphony.xwork2.util.DomHelper.parse(DomHelper.java:117)
  ... 17 more
  </code></pre>