[show] java.lang.IllegalStateException: sendError() forbidden after buffer has
been committed.

java.lang.IllegalStateException: sendError() forbidden after buffer has
been committed.
	at com.caucho.server.connection.AbstractHttpResponse.sendError(AbstractHttpResponse.java:496)
	at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:771)
	at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:506)
	at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
	at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
	at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:87)
	at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:187)
	at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:265)
	at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:273)
	at com.caucho.server.port.TcpConnection.run(TcpConnection.java:682)
	at com.caucho.util.ThreadPool$Item.runTasks(ThreadPool.java:743)
	at com.caucho.util.ThreadPool$Item.run(ThreadPool.java:662)
	at java.lang.Thread.run(Thread.java:722)