DefaultExceptionMapper Errors

I’ve been seeing an odd error pop up in the Logs for a couple of our gateways (one is Ignition 7.9.6 and the other is 7.9.7). When the error triggers, there will often be 10 separate error events that appear in the log, all with the same timestamp. If you expand the error to read the entire error, it will expand all 10 separate error events in the log at the same time (hopefully that makes sense). I just want to make sure there is nothing I need to be worried about with this error and if there is anything I can do to stop it. Any help would be appreciated!

Both gateways are PC’s with one running Windows Server 2012 the other running Windows 7. Both are running Java 8.

Here is the error:

DefaultExceptionMapper
unexpected exception when handling another exception: Header was already written to response!

java.lang.IllegalStateException: Header was already written to response!
at org.apache.wicket.protocol.http.HeaderBufferingWebResponse.checkHeader(HeaderBufferingWebResponse.java:64)
at org.apache.wicket.protocol.http.HeaderBufferingWebResponse.sendError(HeaderBufferingWebResponse.java:105)
at org.apache.wicket.request.http.handler.ErrorCodeRequestHandler.respond(ErrorCodeRequestHandler.java:77)
at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:814)
at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:302)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311)
at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311)
at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:225)
at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:281)
at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:245)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1668)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:581)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:226)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1160)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:511)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1092)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:134)
at org.eclipse.jetty.server.Server.handle(Server.java:518)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:308)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:244)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:273)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:95)
at org.eclipse.jetty.io.SelectChannelEndPoint$2.run(SelectChannelEndPoint.java:93)
at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceAndRun(ExecuteProduceConsume.java:246)
at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:156)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:654)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:572)

Yeah, I’ve seen this, too. Very annoying.

I have noticed with my current project this error is spit out several times, Just last time 7 minutes ago there is 20 or so lines with this error.

I am not sure if it occurs the same time the trial expires after 2 hours, but time stamp seems to be around the same time.

Replying to promote.

We’ve seen this issue ourselves and the log message is not detailed enough to explain what the cause is. Is there any thing that can be done?

Version 7.9.10

This is the same issue as this other thread. It's on our radar, but at a low priority, because it doesn't actually cause any problems.