org.eclipse.birt.report.engine.api.EngineException: The following visibility expression does not evaluate to a legal boolean value: null. (Element ID:1) at 
 org.eclipse.birt.report.engine.executor.ReportItemExecutor.processVisibility(ReportItemExecutor.java:526) at org.eclipse.birt.report.engine.executor.RowExecutor.execute(RowExecutor.java:75) at 
 org.eclipse.birt.report.engine.internal.executor.dup.SuppressDuplicateItemExecutor.execute(SuppressDuplicateItemExecutor.java:43) at 
 org.eclipse.birt.report.engine.internal.executor.wrap.WrappedReportItemExecutor.execute(WrappedReportItemExecutor.java:46) at 
 org.eclipse.birt.report.engine.internal.executor.l18n.LocalizedReportItemExecutor.execute(LocalizedReportItemExecutor.java:34) at org.eclipse.birt.report.engine.layout.html.HTMLAbstractLM.execute(HTMLAbstractLM.java:468) at 
 org.eclipse.birt.report.engine.layout.html.HTMLListingBandLM.intializeHeaderContent(HTMLListingBandLM.java:98) at org.eclipse.birt.report.engine.layout.html.HTMLListingBandLM.initialize(HTMLListingBandLM.java:50) at 
 org.eclipse.birt.report.engine.layout.html.HTMLTableBandLM.initialize(HTMLTableBandLM.java:44) at org.eclipse.birt.report.engine.layout.html.HTMLLayoutManagerFactory.createLayoutManager(HTMLLayoutManagerFactory.java:40) at 
 org.eclipse.birt.report.engine.layout.html.HTMLReportLayoutEngine.createLayoutManager(HTMLReportLayoutEngine.java:138) at 
 org.eclipse.birt.report.engine.layout.html.HTMLBlockStackingLM.layoutNodes(HTMLBlockStackingLM.java:68) at org.eclipse.birt.report.engine.layout.html.HTMLStackingLM.layoutChildren(HTMLStackingLM.java:26) at 
 org.eclipse.birt.report.engine.layout.html.HTMLTableLM.layoutChildren(HTMLTableLM.java:132) at org.eclipse.birt.report.engine.layout.html.HTMLAbstractLM.layout(HTMLAbstractLM.java:140) at 
 org.eclipse.birt.report.engine.layout.html.HTMLBlockStackingLM.layoutNodes(HTMLBlockStackingLM.java:70) at org.eclipse.birt.report.engine.layout.html.HTMLPageLM.layout(HTMLPageLM.java:92) at 
 org.eclipse.birt.report.engine.layout.html.HTMLReportLayoutEngine.layout(HTMLReportLayoutEngine.java:100) at org.eclipse.birt.report.engine.api.impl.RunAndRenderTask.doRun(RunAndRenderTask.java:180) at 
 org.eclipse.birt.report.engine.api.impl.RunAndRenderTask.run(RunAndRenderTask.java:77) at org.eclipse.birt.report.service.ReportEngineService.runAndRenderReport(ReportEngineService.java:929) at 
 org.eclipse.birt.report.service.BirtViewerReportService.runAndRenderReport(BirtViewerReportService.java:973) at 
 org.eclipse.birt.report.service.actionhandler.BirtRunAndRenderActionHandler.__execute(BirtRunAndRenderActionHandler.java:76) at 
 org.eclipse.birt.report.service.actionhandler.AbstractBaseActionHandler.execute(AbstractBaseActionHandler.java:90) at org.eclipse.birt.report.presentation.aggregation.layout.EngineFragment.doService(EngineFragment.java:318) at 
 org.eclipse.birt.report.presentation.aggregation.AbstractBaseFragment.service(AbstractBaseFragment.java:76) at org.eclipse.birt.report.servlet.BirtEngineServlet.__doGet(BirtEngineServlet.java:120) at 
 org.eclipse.birt.report.servlet.BaseReportEngineServlet.doGet(BaseReportEngineServlet.java:185) at org.eclipse.birt.report.servlet.BaseReportEngineServlet.doPost(BaseReportEngineServlet.java:224) at 
 javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.axis.transport.http.AxisServletBase.service(AxisServletBase.java:327) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at 
 org.eclipse.birt.report.servlet.BaseReportEngineServlet.service(BaseReportEngineServlet.java:116) at org.eclipse.equinox.http.registry.internal.ServletManager$ServletWrapper.service(ServletManager.java:180) at 
 org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61) at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:126) at 
 org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:60) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at org.eclipse.equinox.http.jetty.internal.HttpServerManager
 $InternalHttpServiceServlet.service(HttpServerManager.java:317) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:390) at 
 org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at 
 org.mortbay.jetty.Server.handle(Server.java:326) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542) at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:939) at 
 org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:756) at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) at 
 org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409) at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)