Cannot modify component hierarchy after render phase has started

[Maxim Solodovnik <so...@gmail.com>]

Hello,

I'm facing weird "Cannot modify component hierarchy after render phase has
started" exception on simultaneous page access using 2 different browsers
everything works in case there is only one browser, or page being accessed
not "simultaneously"

We are using "single page" application, with async updates via
AjaxBehaviours and WebSockets

Maybe you can propose how to debug this?
Wicket 8.8.8-SNAPSHOT
Tomcat 8.5.12


Here is the stack trace:
org.apache.wicket.WicketRuntimeException: Cannot modify component hierarchy
after render phase has started (page version cant change then anymore)
at org.apache.wicket.Component.checkHierarchyChange(Component.java:3649)
at org.apache.wicket.MarkupContainer.remove(MarkupContainer.java:685)
at
org.apache.wicket.MarkupContainer.addedComponent(MarkupContainer.java:990)
at org.apache.wicket.MarkupContainer.add(MarkupContainer.java:239)
at
org.apache.openmeetings.web.common.MainPanel.onInitialize(MainPanel.java:151)
at org.apache.wicket.Component.fireInitialize(Component.java:878)
at
org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:1037)
at
org.apache.wicket.MarkupContainer.addedComponent(MarkupContainer.java:1014)
at org.apache.wicket.MarkupContainer.add(MarkupContainer.java:239)
at org.apache.openmeetings.web.pages.MainPage.onInitialize(MainPage.java:52)
at org.apache.wicket.Component.fireInitialize(Component.java:878)
at
org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:1037)
at org.apache.wicket.Page.isPageStateless(Page.java:459)
at
org.apache.wicket.request.handler.render.WebPageRenderer.isPageStateless(WebPageRenderer.java:287)
at
org.apache.wicket.request.handler.render.WebPageRenderer.shouldRenderPageAndWriteResponse(WebPageRenderer.java:333)
at
org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:193)
at
org.apache.wicket.core.request.handler.RenderPageRequestHandler.respond(RenderPageRequestHandler.java:202)
at
org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:912)
at
org.apache.wicket.request.RequestHandlerExecutor.execute(RequestHandlerExecutor.java:65)
at
org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:283)
at
org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:253)
at
org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:221)
at
org.apache.wicket.protocol.ws.AbstractUpgradeFilter.processRequestCycle(AbstractUpgradeFilter.java:70)
at
org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:204)
at
org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:286)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at
org.red5.logging.LoggerContextFilter.doFilter(LoggerContextFilter.java:84)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
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:595)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341)
at
org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)
at
org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at
org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)
at
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1441)
at
org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)

-- 
WBR
Maxim aka solomax