net.fortuna.ical4j.model.ValidationException: Property [ATTENDEE] must be specified at least once at net.fortuna.ical4j.util.PropertyValidator.assertOneOrMore(PropertyValidator.java:94) at net.fortuna.ical4j.model.component.VEvent$RequestValidator.validate(VEvent.java:1217) at net.fortuna.ical4j.model.component.CalendarComponent.validate(CalendarComponent.java:83) at net.fortuna.ical4j.model.Calendar.validate(Calendar.java:472) at org.sakaiproject.calendaring.api.ExternalCalendaringServiceImpl.createCalendar(ExternalCalendaringServiceImpl.java:267) at org.sakaiproject.signup.logic.SignupCalendarHelperImpl.createCalendarFile(SignupCalendarHelperImpl.java:193) at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.formatICSAttachment(SignupEmailFacadeImpl.java:808) at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.generateICS(SignupEmailFacadeImpl.java:768) at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.collectAttachments(SignupEmailFacadeImpl.java:746) at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.convertSignupEmail(SignupEmailFacadeImpl.java:720) at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.sendEmail(SignupEmailFacadeImpl.java:361) at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.sendEmail(SignupEmailFacadeImpl.java:380) at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.sendEmailToAllUsers(SignupEmailFacadeImpl.java:537) at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.sendEmailAllUsers(SignupEmailFacadeImpl.java:96) at org.sakaiproject.signup.logic.SignupMeetingServiceImpl.sendEmail(SignupMeetingServiceImpl.java:1072) at org.sakaiproject.signup.tool.jsf.organizer.action.CreateMeetings.postMeetings(CreateMeetings.java:401) at org.sakaiproject.signup.tool.jsf.organizer.action.CreateMeetings.processSaveMeetings(CreateMeetings.java:183) at org.sakaiproject.signup.tool.jsf.NewSignupMeetingBean.processSaveMeetings(NewSignupMeetingBean.java:1861) at org.sakaiproject.signup.tool.jsf.NewSignupMeetingBean.processAssignStudentsAndPublish(NewSignupMeetingBean.java:982) 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:497) at org.apache.el.parser.AstValue.invoke(AstValue.java:245) at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:267) at org.apache.jasper.el.JspMethodExpression.invoke(JspMethodExpression.java:74) at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88) at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) at javax.faces.component.UICommand.broadcast(UICommand.java:387) at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:475) at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:756) at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100) at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:265) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.sakaiproject.util.RequestFilter.doFilter(RequestFilter.java:411) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:374) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318) at org.sakaiproject.signup.tool.SignupServlet.dispatch(SignupServlet.java:216) at org.sakaiproject.jsf.util.JsfTool.doPost(JsfTool.java:257) at org.sakaiproject.signup.tool.SignupServlet.doPost(SignupServlet.java:96) at javax.servlet.http.HttpServlet.service(HttpServlet.java:648) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.sakaiproject.util.RequestFilter.doFilter(RequestFilter.java:411) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:358) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318) at org.sakaiproject.tool.impl.ActiveToolComponent$MyActiveTool.forward(ActiveToolComponent.java:513) at org.sakaiproject.portal.charon.SkinnableCharonPortal.forwardTool(SkinnableCharonPortal.java:1484) at org.sakaiproject.portal.charon.handlers.SiteHandler.doToolBuffer(SiteHandler.java:1162) at org.sakaiproject.portal.charon.handlers.SiteHandler.bufferContent(SiteHandler.java:1018) at org.sakaiproject.portal.charon.handlers.SiteHandler.doSite(SiteHandler.java:484) at org.sakaiproject.portal.charon.handlers.SiteHandler.doGet(SiteHandler.java:263) at org.sakaiproject.portal.charon.handlers.SiteHandler.doGet(SiteHandler.java:151) at org.sakaiproject.portal.charon.handlers.WorksiteHandler.doPost(WorksiteHandler.java:71) at org.sakaiproject.portal.charon.SkinnableCharonPortal.doPost(SkinnableCharonPortal.java:1160) at javax.servlet.http.HttpServlet.service(HttpServlet.java:648) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.sakaiproject.util.RequestFilter.doFilter(RequestFilter.java:460) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668) at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1517) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1474) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) 20-Oct-2016 14:27:02.132 ERROR [http-nio-9080-exec-8] org.sakaiproject.calendaring.api.ExternalCalendaringServiceImpl.toFile Calendar is null, cannot generate ICS file. 20-Oct-2016 14:27:02.133 ERROR [http-nio-9080-exec-8] org.sakaiproject.signup.logic.SignupEmailFacadeImpl.sendEmailToAllUsers Exception: class java.lang.NullPointerException: null 20-Oct-2016 14:27:02.136 ERROR [http-nio-9080-exec-8] org.sakaiproject.signup.tool.jsf.organizer.action.CreateMeetings.postMeetings Email was not sent: an error has occurred. - Some emails may not be sent out due to error. java.lang.Exception: Some emails may not be sent out due to error. at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.sendEmailToAllUsers(SignupEmailFacadeImpl.java:551) at org.sakaiproject.signup.logic.SignupEmailFacadeImpl.sendEmailAllUsers(SignupEmailFacadeImpl.java:96) at org.sakaiproject.signup.logic.SignupMeetingServiceImpl.sendEmail(SignupMeetingServiceImpl.java:1072) at org.sakaiproject.signup.tool.jsf.organizer.action.CreateMeetings.postMeetings(CreateMeetings.java:401) at org.sakaiproject.signup.tool.jsf.organizer.action.CreateMeetings.processSaveMeetings(CreateMeetings.java:183) at org.sakaiproject.signup.tool.jsf.NewSignupMeetingBean.processSaveMeetings(NewSignupMeetingBean.java:1861) at org.sakaiproject.signup.tool.jsf.NewSignupMeetingBean.processAssignStudentsAndPublish(NewSignupMeetingBean.java:982) 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:497) at org.apache.el.parser.AstValue.invoke(AstValue.java:245) at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:267) at org.apache.jasper.el.JspMethodExpression.invoke(JspMethodExpression.java:74) at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88) at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) at javax.faces.component.UICommand.broadcast(UICommand.java:387) at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:475) at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:756) at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100) at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:265) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.sakaiproject.util.RequestFilter.doFilter(RequestFilter.java:411) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:374) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318) at org.sakaiproject.signup.tool.SignupServlet.dispatch(SignupServlet.java:216) at org.sakaiproject.jsf.util.JsfTool.doPost(JsfTool.java:257) at org.sakaiproject.signup.tool.SignupServlet.doPost(SignupServlet.java:96) at javax.servlet.http.HttpServlet.service(HttpServlet.java:648) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.sakaiproject.util.RequestFilter.doFilter(RequestFilter.java:411) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:358) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318) at org.sakaiproject.tool.impl.ActiveToolComponent$MyActiveTool.forward(ActiveToolComponent.java:513) at org.sakaiproject.portal.charon.SkinnableCharonPortal.forwardTool(SkinnableCharonPortal.java:1484) at org.sakaiproject.portal.charon.handlers.SiteHandler.doToolBuffer(SiteHandler.java:1162) at org.sakaiproject.portal.charon.handlers.SiteHandler.bufferContent(SiteHandler.java:1018) at org.sakaiproject.portal.charon.handlers.SiteHandler.doSite(SiteHandler.java:484) at org.sakaiproject.portal.charon.handlers.SiteHandler.doGet(SiteHandler.java:263) at org.sakaiproject.portal.charon.handlers.SiteHandler.doGet(SiteHandler.java:151) at org.sakaiproject.portal.charon.handlers.WorksiteHandler.doPost(WorksiteHandler.java:71) at org.sakaiproject.portal.charon.SkinnableCharonPortal.doPost(SkinnableCharonPortal.java:1160) at javax.servlet.http.HttpServlet.service(HttpServlet.java:648) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.sakaiproject.util.RequestFilter.doFilter(RequestFilter.java:460) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668) at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1517) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1474) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) 20-Oct-2016 14:27:02.187 INFO [http-nio-9080-exec-8] org.sakaiproject.signup.tool.jsf.organizer.action.CreateMeetings.postMeetings title:t4 - UserId:admin - has created new meeting(s) at meeting startTime:Oct 20, 2016 2:00 pm