Hi All, Is this a correct way to pass Decision Table (XLS file) into RuleBase in Drools version 4.0.7? Are the exceptions related to the org.drools.decisiontable.model changes (V2.1 Parameter <file:///D:\Drools\2.1Drools\drools-2.1\docs\apidocs\org\drools\decisiontabl e\model\Parameter.html> , Ruleset <file:///D:\Drools\2.1Drools\drools-2.1\docs\apidocs\org\drools\decisiontabl e\model\Ruleset.html> , Variable <file:///D:\Drools\2.1Drools\drools-2.1\docs\apidocs\org\drools\decisiontabl e\model\Variable.html> vs V4.0.7 DRLOutput <file:///D:\Drools\documentation\apidocs\org\drools\decisiontable\model\DRLO utput.html> , Global <file:///D:\Drools\documentation\apidocs\org\drools\decisiontable\model\Glob al.html> , Package <file:///D:\Drools\documentation\apidocs\org\drools\decisiontable\model\Pack age.html> )? In Drools version 2.1, I can pass the Decision Table (XLS file) into RuleBase and it works great; ... file = new File(dir, XLS _filename); InputStream stream = null; RuleBase ruleBase = null; WorkingMemory wm = null; try { stream = new FileInputStream(file); } catch{... } try{ ruleBase = DecisionTableLoader.loadFromInputStream(stream); wm = ruleBase.newWorkingMemory(); } catch{ ... } return wm; . In Drool version 4.0.7, I tried to pass the Decision Table (XLS file) into RuleBase in the following way and it is not worked yet, though I used the same XLS file; . file = new File(dir, XLS _filename); InputStream stream = null; RuleBase ruleBase = null; WorkingMemory wm = null; try { stream = new FileInputStream(file); } catch{... } try{ ruleBase = RuleBaseFactory.newRuleBase(); PackageBuilder builder = new PackageBuilder(); SpreadsheetCompiler sCompiler = new SpreadsheetCompiler(); String drl = sCompiler.compile(stream, InputType.XLS); builder.addPackageFromDrl(new StringReader(drl)); ruleBase.addPackage(builder.getPackage()); wm = ruleBase.newStatefulSession(); } catch{ ... } return wm; . It complains as following; java.lang.NullPointerException at jxl.biff.drawing.Drawing.initialize(Drawing.java:249) at jxl.biff.drawing.Drawing.<init>(Drawing.java:157) at jxl.read.biff.SheetReader.read(SheetReader.java:737) at jxl.read.biff.SheetImpl.readSheet(SheetImpl.java:620) at jxl.read.biff.WorkbookParser.getSheet(WorkbookParser.java:230) at org.drools.decisiontable.parser.xls.ExcelParser.parseFile(ExcelParser.java:7 9) at org.drools.decisiontable.SpreadsheetCompiler.compile(SpreadsheetCompiler.jav a:89) at org.drools.decisiontable.SpreadsheetCompiler.compile(SpreadsheetCompiler.jav a:68) ... java.lang.IllegalArgumentException: Invalid rule table header cell. Should be in the format of 'RuleTable YourRuleName'. It was: RuleTable (ControlledVocab vocab)] at org.drools.decisiontable.parser.RuleSheetParserUtil.invalidRuleTableDef(Rule SheetParserUtil.java:47) at org.drools.decisiontable.parser.RuleSheetParserUtil.getRuleName(RuleSheetPar serUtil.java:41) at org.drools.decisiontable.parser.DefaultRuleSheetListener.initRuleTable(Defau ltRuleSheetListener.java:256) at org.drools.decisiontable.parser.DefaultRuleSheetListener.processNonRuleCell( DefaultRuleSheetListener.java:307) at org.drools.decisiontable.parser.DefaultRuleSheetListener.newCell(DefaultRule SheetListener.java:232) at org.drools.decisiontable.parser.xls.ExcelParser.newCell(ExcelParser.java:184 ) at org.drools.decisiontable.parser.xls.ExcelParser.processSheet(ExcelParser.jav a:122) at org.drools.decisiontable.parser.xls.ExcelParser.parseFile(ExcelParser.java:8 0) at org.drools.decisiontable.SpreadsheetCompiler.compile(SpreadsheetCompiler.jav a:89) at org.drools.decisiontable.SpreadsheetCompiler.compile(SpreadsheetCompiler.jav a:68) ... Thanks, Hong