I got this when using the attached xls and setting the color of the A1

>>java.lang.NullPointerException >> at org.zkoss.poi.hssf.record.XFExtRecord.cloneXFExtFrom(XFExtRecord.java:91) >> at org.zkoss.poi.hssf.usermodel.HSSFCellStyle.cloneStyleFrom(HSSFCellStyle.java:837) >> at org.zkoss.poi.hssf.usermodel.HSSFCellStyle.cloneStyleFrom(HSSFCellStyle.java:827) >> at org.zkoss.zss.ui.impl.CellVisitorContext.cloneCellStyle(CellVisitorContext.java:76) >> at org.zkoss.zss.ui.impl.Utils$2.handle(Utils.java:239) >> at org.zkoss.zss.ui.impl.CellSelector.doVisit(CellSelector.java:66) >> at org.zkoss.zss.ui.impl.Utils.visitCells(Utils.java:500) >> at org.zkoss.zss.ui.impl.Utils.setFontColor(Utils.java:227) >> at org.zkoss.zss.app.zul.ctrl.SSRectCellStyle.setFontColor(SSRectCellStyle.java:189) >> at org.zkoss.zss.app.zul.ctrl.CellStyleCtrlPanel$7.modify(CellStyleCtrlPanel.java:308) >>
<extendedDataElements name="CommonBaseEventLogRecord:multipleMessageValues" type="string">
<values> at org.zkoss.zss.app.zul.ctrl.DesktopCellStyleContext.modifyStyle(DesktopCellStyleContext.java:48)
>> at org.zkoss.zss.app.zul.ctrl.CellStyleCtrlPanel.onChange$fontColorBtn(CellStyleCtrlPanel.java:305)
>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>> at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48)
>> at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
>> at java.lang.reflect.Method.invoke(Method.java:600)
>> at org.zkoss.zk.ui.impl.EventProcessor.process0(EventProcessor.java:205)
>> at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:138)
>> at org.zkoss.zk.ui.event.Events.sendEvent(Events.java:306)
>> at org.zkoss.zk.ui.event.Events.sendEvent(Events.java:329)
>> at org.zkoss.zk.ui.AbstractComponent$ForwardListener.onEv</values>
<values>ent(AbstractComponent.java:3048)
>> at org.zkoss.zk.ui.impl.EventProcessor.process0(EventProcessor.java:192)
>> at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:138)
>> at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1612)
>> at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1396)
>> at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1109)
>> at org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:569)
>> at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:463)
>> at org.zkoss.xpage.core.web.AuServlet.doGet(AuServlet.java:72)
>> at org.zkoss.xpage.core.web.AuServlet.doPost(AuServlet.java:92)
>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:713)
>> at javax.servlet.http.HttpServlet.service</values>
<values>(HttpServlet.java:806)
>> at org.zkoss.xpage.core.XspServletFactory$XspAuServlet.doGet(XspServletFactory.java:145)
>> at org.zkoss.xpage.core.XspServletFactory$XspAuServlet.doPost(XspServletFactory.java:134)
>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:713)
>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:806)
>> at com.ibm.designer.runtime.domino.adapter.ComponentModule.invokeServlet(ComponentModule.java:538)
>> at com.ibm.domino.xsp.module.nsf.NSFComponentModule.invokeServlet(NSFComponentModule.java:1140)
>> at com.ibm.designer.runtime.domino.adapter.ComponentModule$AdapterInvoker.invokeServlet(ComponentModule.java:803)
>> at com.ibm.designer.runtime.domino.adapter.ComponentModule$ServletInvoker.doService(ComponentModule.java:758)
>> at com.ibm.designer.runtime.domino.adapter.ComponentModule.doService(Component</values>
<values>Module.java:527)
>> at com.ibm.domino.xsp.module.nsf.NSFComponentModule.doService(NSFComponentModule.java:1124)
>> at com.ibm.domino.xsp.module.nsf.NSFService.doServiceInternal(NSFService.java:513)
>> at com.ibm.domino.xsp.module.nsf.NSFService.doService(NSFService.java:342)
>> at com.ibm.designer.runtime.domino.adapter.LCDEnvironment.doService(LCDEnvironment.java:304)
>> at com.ibm.designer.runtime.domino.adapter.LCDEnvironment.service(LCDEnvironment.java:261)
>> at com.ibm.domino.xsp.bridge.http.engine.XspCmdManager.service(XspCmdManager.java:291)
</values>
</extendedDataElements>