BigBlueButton: RS if meeting is not accessible

2020-04-30 16:26:09.335 [ajp-nio2-8014-exec-52] ERROR Window ^%^ I881078-J65409
 org.olat.core.gui.components.Window
 https://xyz.olat.com/auth/RepositoryEntry/210239528/CourseNode/101461952473773
 Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.129 Safari/537.36
 **RedScreen** target with name: 'meeting.join.button', was invisible, but called to dispatch ::_:: ::_::
org.olat.core.logging.OLATRuntimeException: target with name: 'meeting.join.button', was invisible, but called to dispatch
 at org.olat.core.gui.components.Window.doDispatchToComponent(Window.java:1199)
 at org.olat.core.gui.components.Window.dispatchRequest(Window.java:681)
 at org.olat.core.gui.components.Window.doDispatchRequest(Window.java:284)
 at org.olat.core.gui.components.AbstractComponent.dispatchRequest(AbstractComponent.java:193)
 at org.olat.dispatcher.AuthenticatedDispatcher.processValidDispatchURI(AuthenticatedDispatcher.java:263)
 at org.olat.dispatcher.AuthenticatedDispatcher.execute(AuthenticatedDispatcher.java:184)
 at org.olat.core.servlets.OpenOLATServlet.executeUserRequest(OpenOLATServlet.java:269)
 at org.olat.core.servlets.OpenOLATServlet.doGet(OpenOLATServlet.java:201)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
 at org.olat.core.servlets.OpenOLATServlet.service(OpenOLATServlet.java:160)
 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.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.olat.core.servlets.HeadersFilter.doFilter(HeadersFilter.java:95)
 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:493)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
 at org.apache.coyote.ajp.AjpProcessor.service(AjpProcessor.java:479)
 at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
 at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:800)
 at org.apache.tomcat.util.net.Nio2Endpoint$SocketProcessor.doRun(Nio2Endpoint.java:1699)
 at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
 at org.apache.tomcat.util.net.AbstractEndpoint.processSocket(AbstractEndpoint.java:1050)
 at org.apache.tomcat.util.net.Nio2Endpoint$Nio2SocketWrapper$4.completed(Nio2Endpoint.java:630)
 at org.apache.tomcat.util.net.Nio2Endpoint$Nio2SocketWrapper$4.completed(Nio2Endpoint.java:608)
 at sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:126)
 at sun.nio.ch.Invoker$2.run(Invoker.java:218)
 at sun.nio.ch.AsynchronousChannelGroupImpl$1.run(AsynchronousChannelGroupImpl.java:112)
 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
 at java.util.concurrent.ThreadPoolExecutor$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.Exception: olat_rtexception_stackgenerator
 at org.olat.core.logging.OLATRuntimeException.<init>(OLATRuntimeException.java:57)
 at org.olat.core.logging.OLATRuntimeException.<init>(OLATRuntimeException.java:79) ... 41 more

Error#: I1146556-J214431 Identity: 357367879 Category/Class: org.olat.core.gui.exception.ExceptionWindowController
Referer: https://xyz.ch/auth/RepositoryEntry/381157381/CourseNode/101494891836933
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.1.2 Safari/605.1.15 Exception: ExceptionWindowController: Throwable occurred, logging the full stacktrace: java.lang.NullPointerException
 at org.olat.modules.bigbluebutton.manager.BigBlueButtonManagerImpl.getMeeting(BigBlueButtonManagerImpl.java:325)
 at org.olat.modules.bigbluebutton.ui.BigBlueButtonMeetingController.doJoin(BigBlueButtonMeetingController.java:233)
 at org.olat.modules.bigbluebutton.ui.BigBlueButtonMeetingController.event(BigBlueButtonMeetingController.java:222)
 at org.olat.core.gui.control.DefaultController.dispatchEvent(DefaultController.java:206)
 at org.olat.core.gui.components.AbstractComponent$1.run(AbstractComponent.java:240)
 at org.olat.core.logging.activity.ThreadLocalUserActivityLoggerInstaller.runWithUserActivityLogger(ThreadLocalUserActivityLoggerInstaller.java:108)
 at org.olat.core.gui.components.AbstractComponent.fireEvent(AbstractComponent.java:238)
 at org.olat.core.gui.components.link.Link.dispatch(Link.java:207)
 at org.olat.core.gui.components.link.Link.doDispatchRequest(Link.java:194)
 at org.olat.core.gui.components.AbstractComponent.dispatchRequest(AbstractComponent.java:193)
 at org.olat.core.gui.components.Window.doDispatchToComponent(Window.java:1218)
 at org.olat.core.gui.components.Window.dispatchRequest(Window.java:681)
 at org.olat.core.gui.components.Window.doDispatchRequest(Window.java:284)
 at org.olat.core.gui.components.AbstractComponent.dispatchRequest(AbstractComponent.java:193)
 at org.olat.dispatcher.AuthenticatedDispatcher.processValidDispatchURI(AuthenticatedDispatcher.java:263)
 at org.olat.dispatcher.AuthenticatedDispatcher.execute(AuthenticatedDispatcher.java:184)
 at org.olat.core.servlets.OpenOLATServlet.executeUserRequest(OpenOLATServlet.java:269)
 at org.olat.core.servlets.OpenOLATServlet.doGet(OpenOLATServlet.java:201)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
 at org.olat.core.servlets.OpenOLATServlet.service(OpenOLATServlet.java:160)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)