error upload (attach files)

Bonjour, je rencentre une ereur quand j'esaie de attacher un fichier. L'ereur reçut est de type Detailed information: Error number 0 in 11: Uncaught exception Wrapped Exception: null com.xpn.xwiki.XWikiException: Error number 0 in 11: Uncaught exception Wrapped Exception: null at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:162) at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431) at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236) at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196) at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432) at javax.servlet.http.HttpServlet.service(HttpServlet.java:763) at javax.servlet.http.HttpServlet.service(HttpServlet.java:856) at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:243) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAsPrivileged(Subject.java:517) at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:275) at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:161) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:245) at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:50) at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:156) at java.security.AccessController.doPrivileged(Native Method) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:152) at com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:127) at sun.reflect.GeneratedMethodAccessor92.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:243) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAsPrivileged(Subject.java:517) at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:275) at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:217) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:197) at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:50) at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:156) at java.security.AccessController.doPrivileged(Native Method) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:152) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178) at org.objectweb.jonas.web.catalina55.ResetAuthenticationValve.invoke(ResetAuthenticationValve.java:62) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869) at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664) at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527) at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684) at java.lang.Thread.run(Thread.java:595) Wrapped Exception: java.lang.NullPointerException at com.xpn.xwiki.web.UploadAction.action(UploadAction.java:51) at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:145) at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431) at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236) at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196) at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432) at javax.servlet.http.HttpServlet.service(HttpServlet.java:763) at javax.servlet.http.HttpServlet.service(HttpServlet.java:856) at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:243) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAsPrivileged(Subject.java:517) at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:275) at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:161) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:245) at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:50) at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:156) at java.security.AccessController.doPrivileged(Native Method) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:152) at com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:127) au niveu des log de jonas j'ai ça Wrapped Exception: java.lang.NullPointerException at com.xpn.xwiki.web.UploadAction.action(UploadAction.java:51) at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:145) at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431) at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236) at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196) at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432) at javax.servlet.http.HttpServlet.service(HttpServlet.java:763) at javax.servlet.http.HttpServlet.service(HttpServlet.java:856) at sun.reflect.GeneratedMethodAccessor93.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:243) on d'ou peut venir le probleme Pascal GARCIA