org.apache.wicket.WicketRuntimeException: Method onRequest of interface org.apache.wicket.behavior.IBehaviorListener targeted at org.apache.wicket.ajax.markup.html.form.AjaxButton$1@7154528a on component [AjaxButton [Component id = continuebutton]] threw an exception at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:268) at org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:241) at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.invokeListener(ListenerInterfaceRequestHandler.java:250) at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.respond(ListenerInterfaceRequestHandler.java:236) at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:890) at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64) at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:261) at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:218) at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:289) at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:259) at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:201) at org.apache.wicket.protocol.http.WicketServlet.doPost(WicketServlet.java:159) at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.sakaiproject.util.RequestFilter.doFilter(RequestFilter.java:426) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:470) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:356) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:316) at org.sakaiproject.tool.impl.ActiveToolComponent$MyActiveTool.forward(ActiveToolComponent.java:513) at org.sakaiproject.portal.charon.SkinnableCharonPortal.forwardTool(SkinnableCharonPortal.java:1488) at org.sakaiproject.portal.charon.handlers.SiteHandler.doToolBuffer(SiteHandler.java:1228) at org.sakaiproject.portal.charon.handlers.SiteHandler.bufferContent(SiteHandler.java:1062) at org.sakaiproject.portal.charon.handlers.SiteHandler.doSite(SiteHandler.java:491) at org.sakaiproject.portal.charon.handlers.SiteHandler.doGet(SiteHandler.java:267) at org.sakaiproject.portal.charon.handlers.SiteHandler.doGet(SiteHandler.java:155) at org.sakaiproject.portal.charon.handlers.WorksiteHandler.doPost(WorksiteHandler.java:69) at org.sakaiproject.portal.charon.SkinnableCharonPortal.doPost(SkinnableCharonPortal.java:1172) at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.sakaiproject.util.RequestFilter.doFilter(RequestFilter.java:475) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:677) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748) Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:258) ... 58 more Caused by: java.lang.NullPointerException at org.sakaiproject.gradebookng.business.importExport.UsernameIdentifier.getUser(UsernameIdentifier.java:65) at org.sakaiproject.gradebookng.business.importExport.UsernameIdentifier.validateUsers(UsernameIdentifier.java:84) at org.sakaiproject.gradebookng.business.importExport.UsernameIdentifier.(UsernameIdentifier.java:46) at org.sakaiproject.gradebookng.business.model.ImportedSpreadsheetWrapper.setRows(ImportedSpreadsheetWrapper.java:58) at org.sakaiproject.gradebookng.business.util.ImportGradesHelper.parseCsv(ImportGradesHelper.java:193) at org.sakaiproject.gradebookng.business.util.ImportGradesHelper.parseImportedGradeFile(ImportGradesHelper.java:134) at org.sakaiproject.gradebookng.tool.panels.importExport.GradeImportUploadStep$UploadForm.processUploadedFile(GradeImportUploadStep.java:140) at org.sakaiproject.gradebookng.tool.panels.importExport.GradeImportUploadStep$UploadForm$2.onSubmit(GradeImportUploadStep.java:113) at org.apache.wicket.ajax.markup.html.form.AjaxButton$1.onSubmit(AjaxButton.java:108) at org.apache.wicket.ajax.form.AjaxFormSubmitBehavior$AjaxFormSubmitter.onSubmit(AjaxFormSubmitBehavior.java:215) at org.apache.wicket.markup.html.form.Form.delegateSubmit(Form.java:1305) at org.apache.wicket.markup.html.form.Form.process(Form.java:966) at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:788) at org.apache.wicket.ajax.form.AjaxFormSubmitBehavior.onEvent(AjaxFormSubmitBehavior.java:171) at org.apache.wicket.ajax.AjaxEventBehavior.respond(AjaxEventBehavior.java:145) at org.apache.wicket.ajax.AbstractDefaultAjaxBehavior.onRequest(AbstractDefaultAjaxBehavior.java:654) ... 63 more