SEVERE: null when eval INDIRECT(C$46)
java.lang.NullPointerException
at org.zkoss.poi.ss.formula.OperationEvaluationContext.getDynamicReference(OperationEvaluationContext.java:183)
at org.zkoss.poi.ss.formula.functions.Indirect.evaluateIndirect(Indirect.java:126)
at org.zkoss.poi.ss.formula.functions.Indirect.evaluate(Indirect.java:76)
at org.zkoss.poi.ss.formula.OperationEvaluatorFactory.evaluate(OperationEvaluatorFactory.java:127)
at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluateFormula(WorkbookEvaluator.java:578)
at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluateAnyPtgs(WorkbookEvaluator.java:1053)
at org.zkoss.poi.ss.formula.WorkbookEvaluator.evaluatePtgs(WorkbookEvaluator.java:973)
at org.zkoss.zssex.formula.FormulaEngineEx.evaluateFormulaExpression(FormulaEngineEx.java:217)
at org.zkoss.zss.model.impl.sys.formula.FormulaEngineImpl.evaluateFormula(FormulaEngineImpl.java:433)
at org.zkoss.zss.model.impl.sys.formula.FormulaEngineImpl.evaluate(FormulaEngineImpl.java:338)
at org.zkoss.zss.model.impl.DataValidationImpl.evalFormula(DataValidationImpl.java:470)
at org.zkoss.zss.model.impl.DataValidationImpl.getNumOfValue1(DataValidationImpl.java:346)
at org.zkoss.zssex.ui.impl.DataValidationHandlerImpl.getValidationList(DataValidationHandlerImpl.java:119)
at org.zkoss.zssex.ui.impl.DataValidationHandlerImpl.convertDataValidationToJSON(DataValidationHandlerImpl.java:94)
at org.zkoss.zssex.ui.impl.DataValidationHandlerImpl.convertDataValidationToJSON(DataValidationHandlerImpl.java:64)
at org.zkoss.zssex.ui.impl.DataValidationHandlerImpl.loadDataValidtionJASON(DataValidationHandlerImpl.java:56)
at org.zkoss.zss.ui.Spreadsheet.updateSheetAttributes(Spreadsheet.java:999)
at org.zkoss.zss.ui.Spreadsheet.setSelectedSheetDirectly(Spreadsheet.java:939)
at org.zkoss.zss.ui.Spreadsheet.access$45(Spreadsheet.java:920)
at org.zkoss.zss.ui.Spreadsheet$ExtraCtrl.setSelectedSheetDirectly(Spreadsheet.java:3768)
at org.zkoss.zss.ui.au.in.SelectSheetCommand.process(SelectSheetCommand.java:83)
at org.zkoss.zss.ui.Spreadsheet.service(Spreadsheet.java:5039)
at org.zkoss.zk.ui.impl.DesktopImpl.service(DesktopImpl.java:710)