I am getting the following error in Mendix 4.0.1 when trying to use the following line of java code to export to excel: ExportManagerModule.generateXLS(this.getContext(), exportDoc, fileName, oqlQuery, autoSizeColumns); Can someone help me with the following error: SLF4J: Class path contains multiple SLF4J bindings. SLF4J: Found binding in [jar:file:/C:/Program%20Files%20(x86)/Mendix/4.0.1/server/appcontainer.jar!/org/slf4j/impl/StaticLoggerBinder.class] SLF4J: Found binding in [jar:file:/C:/Program%20Files%20(x86)/Mendix/4.0.1/server/lib/appcontainer.jar!/org/slf4j/impl/StaticLoggerBinder.class] SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation. [ERROR] [8/23/12 3:10 PM] [akka:event-driven:dispatcher:request-dispatching-38] [LocalActorRef] null java.lang.ExceptionInInitializerError at org.apache.poi.hssf.model.LinkTable$ExternalBookBlock.<init>(LinkTable.java:120) at org.apache.poi.hssf.model.LinkTable.<init>(LinkTable.java:253) at org.apache.poi.hssf.model.InternalWorkbook.getOrCreateLinkTable(InternalWorkbook.java:1761) at org.apache.poi.hssf.model.InternalWorkbook.createWorkbook(InternalWorkbook.java:423) at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:163) at kM.a(SourceFile:45) at kM.a(SourceFile:128) at com.mendix.modules.exportmanager.ExportManagerModule.generateXLS(SourceFile:117) at excelexport.actions.ExportAction.executeAction(ExportAction.java:85) at excelexport.actions.ExportAction.executeAction(ExportAction.java:1) at com.mendix.systemwideinterfaces.core.UserAction.execute(SourceFile:57) at com.mendix.core.actionmanagement.CoreAction.call(SourceFile:457) at hC.b(SourceFile:182) at com.mendix.core.Core.execute(SourceFile:219) at lg.a(SourceFile:70) at mf.a(SourceFile:73) at me.executeAction(SourceFile:101) at com.mendix.systemwideinterfaces.core.UserAction.execute(SourceFile:57) at com.mendix.core.actionmanagement.CoreAction.call(SourceFile:457) at hC.b(SourceFile:182) at com.mendix.core.Core.execute(SourceFile:219) at gm.execute(SourceFile:186) at iW.a(SourceFile:285) at ja$g.a(SourceFile:126) at ja$g$a.a(SourceFile:118) at ja$g$a.apply(SourceFile:116) at akka.actor.Actor$class.apply(Actor.scala:545) at ja$g.apply(SourceFile:112) at akka.actor.LocalActorRef.invoke(ActorRef.scala:910) at akka.dispatch.MessageInvocation.invoke(MessageHandling.scala:25) at akka.dispatch.ExecutableMailbox$class.processMailbox(ExecutorBasedEventDrivenDispatcher.scala:223) at akka.dispatch.ExecutorBasedEventDrivenDispatcher$$anon$4.processMailbox(ExecutorBasedEventDrivenDispatcher.scala:123) at akka.dispatch.ExecutableMailbox$class.run(ExecutorBasedEventDrivenDispatcher.scala:195) at akka.dispatch.ExecutorBasedEventDrivenDispatcher$$anon$4.run(ExecutorBasedEventDrivenDispatcher.scala:123) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) I think this may have to do with having 4.1.0 installed on my machine as well. Because i ran the code in 4.1.0 and it worked fine. Looks like it is trying to use the wrong library or something.