I have a form where I'am uploading an spreadsheet file, with .xls and .xlsx extension. So for parsing this files I'am using apache poi library. So when I upload .xls file everything is fine, the file is parsed, passed to a microflow and data persisted into db. But when I try to import a .xlsx file with the same data format I got this error: com.mendix.core.CoreRuntimeException: java.security.AccessControlException: access denied (java.util.PropertyPermission java.io.tmpdir read) This is part of my code InputStream in = Core.getFileDocumentContent(getContext(), this.file.getMendixObject()); System.out.println(this.file.getName(getContext())); Workbook wb = WorkbookFactory.create(in); Sheet sheet = wb.getSheetAt(0); And this is hole stacktrace: com.mendix.core.CoreRuntimeException: java.security.AccessControlException: access denied (java.util.PropertyPermission java.io.tmpdir read) at {} at Module.ImportExcelFileSaveOfferings (JavaAction : 'Call 'parseExcel'') Advanced stacktrace: at mg.a(SourceFile:188) Caused by: com.mendix.core.CoreException: com.mendix.core.CoreRuntimeException: java.security.AccessControlException: access denied (java.util.PropertyPermission java.io.tmpdir read) at com.mendix.core.Core.execute(SourceFile:225) Caused by: com.mendix.core.CoreRuntimeException: java.security.AccessControlException: access denied (java.util.PropertyPermission java.io.tmpdir read) at hC.b(SourceFile:194) Caused by: java.security.AccessControlException: access denied (java.util.PropertyPermission java.io.tmpdir read) at java.security.AccessControlContext.checkPermission(Unknown Source) at java.security.AccessController.checkPermission(Unknown Source) at java.lang.SecurityManager.checkPermission(Unknown Source) at java.lang.SecurityManager.checkPropertyAccess(Unknown Source) at java.lang.System.getProperty(Unknown Source) at org.apache.poi.util.TempFile.createTempFile(TempFile.java:42) at org.apache.poi.util.PackageHelper.createTempFile(PackageHelper.java:101) at org.apache.poi.util.PackageHelper.clone(PackageHelper.java:44) at org.apache.poi.POIXMLDocument.ensureWriteAccess(POIXMLDocument.java:185) at org.apache.poi.xssf.usermodel.XSSFWorkbook.<init>(XSSFWorkbook.java:169) at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:63) at module.actions.parseExcel.executeAction(parseExcel.java:62) at module.actions.parseExcel.executeAction(parseExcel.java:1) at com.mendix.systemwideinterfaces.core.UserAction.execute(SourceFile:57) at com.mendix.core.actionmanagement.CoreAction.call(SourceFile:457) at hC.b(SourceFile:183) at com.mendix.core.Core.execute(SourceFile:219) at lh.a(SourceFile:69) at mg.a(SourceFile:73) at mf.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:183) at com.mendix.core.Core.execute(SourceFile:219) at gm.execute(SourceFile:186) at iW.a(SourceFile:304) at com.mendix.externalinterface.connector.RequestDispatching$Worker.a(SourceFile:141) at com.mendix.externalinterface.connector.RequestDispatching$Worker$a.a(SourceFile:133) at com.mendix.externalinterface.connector.RequestDispatching$Worker$a.apply(SourceFile:131) at akka.actor.Actor$class.apply(Actor.scala:545) at com.mendix.externalinterface.connector.RequestDispatching$Worker.apply(SourceFile:127) at akka.actor.LocalActorRef.invoke(ActorRef.scala:910) at akka.dispatch.MessageInvocation.invoke(MessageHandling.scala:25) at akka.dispatch.ExecutableMailbox$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) at akka.dispatch.MonitorableThread.run(ThreadPoolBuilder.scala:192) Does anyone know why is this happening. Thanks in advance