Caused by: java.lang.NullPointerException at org.eclipse.birt.core.util.IOUtil.writeInt(IOUtil.java:226) at org.eclipse.birt.core.util.IOUtil.writeObject(IOUtil.java:674) at org.eclipse.birt.data.engine.executor.transform.SimpleGroupCalculator.next(SimpleGroupCalculator.java:233) at org.eclipse.birt.data.engine.executor.transform.SimpleResultSet.next(SimpleResultSet.java:562) at org.eclipse.birt.data.engine.executor.transform.ResultSetWrapper.next(ResultSetWrapper.java:81) at org.eclipse.birt.data.engine.impl.ResultIterator.hasNextRow(ResultIterator.java:584) at org.eclipse.birt.data.engine.impl.ResultIterator.nextRow(ResultIterator.java:525) at org.eclipse.birt.data.engine.impl.ResultIterator.next(ResultIterator.java:475) at org.eclipse.birt.report.engine.data.dte.QueryResultSet.next(QueryResultSet.java:191) at org.eclipse.birt.report.engine.executor.ListingElementExecutor.hasNextChild(ListingElementExecutor.java:244) at org.eclipse.birt.report.engine.internal.executor.wrap.WrappedReportItemExecutor.hasNextChild(WrappedReportItemExecutor.java:86) at org.eclipse.birt.report.engine.internal.executor.wrap.WrappedReportItemExecutor.hasNextChild(WrappedReportItemExecutor.java:86) at org.eclipse.birt.report.engine.layout.html.HTMLBlockStackingLM.layoutNodes(HTMLBlockStackingLM.java:62) 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)