# DefaultExceptionMapper on 7.9.9 **URL:** \ **Category:** Ignition\ **Created:** [October 25, 2018, 3:02pm UTC](https://forum.inductiveautomation.com/t/defaultexceptionmapper-on-7-9-9/20373 "2018-10-25T15:02:56Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Mau89](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mau89/32/20680_2.png) [@Mau89](https://forum.inductiveautomation.com/u/Mau89)\ **Post date:** [October 25, 2018, 3:02pm UTC](https://forum.inductiveautomation.com/t/defaultexceptionmapper-on-7-9-9/20373/1 "2018-10-25T15:02:56Z")
Hi everyone, I found this error on gatewy log. ```auto DefaultExceptionMapper 25Oct2018 16:37:11 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$HandlerExecutor.respond(RequestCycle.java:814) at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64) at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:302) at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311) at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311) at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311) at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311) at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311) at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311) at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311) at org.apache.wicket.request.cycle.RequestCycle.executeExceptionRequestHandler(RequestCycle.java:311) at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:225) at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:281) at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188) at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:245) at com.inductiveautomation.ignition.gateway.bootstrap.SRFilter.doFilter(SRFilter.java:80) at org.eclipse.jetty.servlet.ServletHandler$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) ``` Someone know what it means? ---
**Author:** ![AIO](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/aio/32/87549_2.png) [@AIO](https://forum.inductiveautomation.com/u/AIO)\ **Post date:** [October 25, 2018, 6:39pm UTC](https://forum.inductiveautomation.com/t/defaultexceptionmapper-on-7-9-9/20373/2 "2018-10-25T18:39:43Z")
I had this same issue and worked with support on it. It came down to logging-in to the gateway webpage with firefox causing this problem. It only occurs occasionally on login from a firefox browser. At least for me. ---
**Author:** ![Mau89](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mau89/32/20680_2.png) [@Mau89](https://forum.inductiveautomation.com/u/Mau89)\ **Post date:** [October 30, 2018, 2:27pm UTC](https://forum.inductiveautomation.com/t/defaultexceptionmapper-on-7-9-9/20373/3 "2018-10-30T14:27:18Z")
I had this problem with chrome. ---
**Author:** ![AIO](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/aio/32/87549_2.png) [@AIO](https://forum.inductiveautomation.com/u/AIO)\ **Post date:** [October 30, 2018, 3:23pm UTC](https://forum.inductiveautomation.com/t/defaultexceptionmapper-on-7-9-9/20373/4 "2018-10-30T15:23:02Z")
Disregard, I misread the logs.