1	2
1	

>>java.lang.NullPointerException
>>	at org.zkoss.poi.hssf.usermodel.HSSFEvaluationCell.getStringCellValue(HSSFEvaluationCell.java:70)
>>	at org.zkoss.poi.ss.formula.WorkbookEvaluator.getValueFromNonFormulaCell(WorkbookEvaluator.java:406)
>>	at org.zkoss.poi.ss.formula.EvaluationCache.notifyUpdateCell(EvaluationCache.java:83)
>>	at org.zkoss.poi.ss.formula.WorkbookEvaluator.notifyUpdateCell(WorkbookEvaluator.java:229)
>>	at org.zkoss.poi.hssf.usermodel.HSSFFormulaEvaluator.notifySetFormula(HSSFFormulaEvaluator.java:164)
>>	at org.zkoss.zss.model.sys.impl.BookHelper.clearFormulaCache(BookHelper.java:314)
>>	at org.zkoss.zss.model.sys.impl.BookHelper.reevaluateAndNotify(BookHelper.java:489)
>>	at org.zkoss.zss.model.sys.impl.XRangeImpl.reevaluateAndNotify(XRangeImpl.java:428)
>>	at org.zkoss.zss.model.sys.impl.XRangeImpl.setEditText(XRangeImpl.java:382)
>>	at org.zkoss.zss.api.impl.RangeImpl.setCellEditText(RangeImpl.java:610)
>>	at org.zkoss.zss.ui.impl.undo.CellEditTextAction.applyAction(CellEditTextAction.java:51)
>>	at org.zkoss.zss.ui.impl.undo.AbstractEditTextAction.doAction(AbstractEditTextAction.java:82)
>>	at org.zkoss.zssex.ui.impl.UndoableActionManagerImpl.doAction(UndoableActionManagerImpl.java:50)
>>	at org.zkoss.zss.ui.Spreadsheet.processStopEditing0(Spreadsheet.java:4386)
>>	at org.zkoss.zss.ui.Spreadsheet.processStopEditing(Spreadsheet.java:4338)
>>	at org.zkoss.zss.ui.Spreadsheet.access$45(Spreadsheet.java:4336)
>>	at org.zkoss.zss.ui.Spreadsheet$2.onEvent(Spreadsheet.java:350)
>>	at org.zkoss.zk.ui.AbstractComponent.onEvent(AbstractComponent.java:2748)
>>	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2719)
>>	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2660)
>>	at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:136)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1720)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1505)
>>	at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1215)
>>	at org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:600)
>>	at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:482)
>>	at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:491)
>>	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
>>	at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
>>	at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
>>	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:401)
>>	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
>>	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
>>	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
>>	at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
>>	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
>>	at org.mortbay.jetty.Server.handle(Server.java:326)
>>	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
>>	at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:945)
>>	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:410)
>>	at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)