I am trying to implement an open source ocr solution for my mendix app. As a first step im putting required jar files inside my userlib folder which is under MyProject/userlib and than i am adding these jar files manually to the build path in eclipse. However when i run my mendix project within eclipse it is working as expected. But whenever i am trying to run localy from modeler, mendix unable to find my external jars. So what is the proper way for using external jars? As far as i understand from an old forum post all i have to do is putting my jar files inside my userlib folder and it will automatically added my buildpath but this way doesnt work for me. Here is the stack trace and tess4j is the external jar im using, Uncaught fatal error from thread [MxRuntimeSystem-akka.actor.action-dispatcher-14] shutting down ActorSystem [MxRuntimeSystem] -------- java.lang.NoClassDefFoundError: net/sourceforge/tess4j/TesseractException at halkbankccasmodule.actions.OCRAction.executeAction(OCRAction.java:34) at halkbankccasmodule.actions.OCRAction.executeAction(OCRAction.java:1) at com.mendix.systemwideinterfaces.core.UserAction.execute(UserAction.java:53) at com.mendix.core.actionmanagement.CoreAction.doCall(CoreAction.java:291) at com.mendix.core.actionmanagement.CoreAction.call(CoreAction.java:276) at com.mendix.core.actionmanagement.ActionManager$1.execute(ActionManager.java:204) at com.mendix.util.classloading.Runner.doRunUsingClassLoaderOf(Runner.java:37) at com.mendix.core.actionmanagement.ActionManager.executeSync(ActionManager.java:199) at com.mendix.core.component.InternalCore.execute(InternalCore.java:263) at com.mendix.modules.microflowengine.actions.actioncall.JavaAction.execute(JavaAction.scala:42) at com.mendix.modules.microflowengine.microflow.impl.MicroflowObject.execute(MicroflowObject.java:49) at com.mendix.modules.microflowengine.microflow.impl.MicroflowImpl.executeAfterBreakingIfNecessary(MicroflowImpl.java:193) at com.mendix.modules.microflowengine.microflow.impl.MicroflowImpl.executeAction(MicroflowImpl.java:148) at com.mendix.systemwideinterfaces.core.UserAction.execute(UserAction.java:53) at com.mendix.core.actionmanagement.CoreAction.doCall(CoreAction.java:291) at com.mendix.core.actionmanagement.CoreAction.call(CoreAction.java:276) at com.mendix.core.actionmanagement.ActionManager$1.execute(ActionManager.java:204) at com.mendix.util.classloading.Runner.doRunUsingClassLoaderOf(Runner.java:37) at com.mendix.core.actionmanagement.ActionManager.executeSync(ActionManager.java:199) at com.mendix.core.component.InternalCore.execute(InternalCore.java:263) at com.mendix.webui.actions.client.ExecuteAction.execute(ExecuteAction.java:135) at com.mendix.webui.requesthandling.ClientRequestHandler$$anonfun$handleRequest$1.apply$mcV$sp(ClientRequestHandler.scala:300) at com.mendix.webui.requesthandling.ClientRequestHandler$$anonfun$handleRequest$1.apply(ClientRequestHandler.scala:293) at com.mendix.webui.requesthandling.ClientRequestHandler$$anonfun$handleRequest$1.apply(ClientRequestHandler.scala:293) at com.mendix.core.session.Worker$$anonfun$receive$3$$anonfun$2$$anon$1.execute(ActionDispatching.scala:151) at com.mendix.util.classloading.Runner.doRunUsingClassLoaderOf(Runner.java:37) at com.mendix.core.session.Worker$$anonfun$receive$3$$anonfun$2.apply(ActionDispatching.scala:153) at scala.util.Try$.apply(Try.scala:191) at com.mendix.core.session.Worker$$anonfun$receive$3.applyOrElse(ActionDispatching.scala:147) at akka.actor.Actor$class.aroundReceive(Actor.scala:465) at com.mendix.core.session.Worker.aroundReceive(ActionDispatching.scala:140) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516) at akka.actor.ActorCell.invoke(ActorCell.scala:487) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238) at akka.dispatch.Mailbox.run(Mailbox.scala:220) at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393) at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) Caused by: java.lang.ClassNotFoundException: net.sourceforge.tess4j.TesseractException not found by project [92] at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1532) at org.apache.felix.framework.BundleWiringImpl.access$400(BundleWiringImpl.java:75) at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:1955) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) at halkbankccasmodule.actions.OCRAction.executeAction(OCRAction.java:34) at halkbankccasmodule.actions.OCRAction.executeAction(OCRAction.java:1) at com.mendix.systemwideinterfaces.core.UserAction.execute(UserAction.java:53) at com.mendix.core.actionmanagement.CoreAction.doCall(CoreAction.java:291) at com.mendix.core.actionmanagement.CoreAction.call(CoreAction.java:276) at com.mendix.core.actionmanagement.ActionManager$1.execute(ActionManager.java:204) at com.mendix.util.classloading.Runner.doRunUsingClassLoaderOf(Runner.java:37) at com.mendix.core.actionmanagement.ActionManager.executeSync(ActionManager.java:199) at com.mendix.core.component.InternalCore.execute(InternalCore.java:263) at com.mendix.modules.microflowengine.actions.actioncall.JavaAction.execute(JavaAction.scala:42) at com.mendix.modules.microflowengine.microflow.impl.MicroflowObject.execute(MicroflowObject.java:49) at com.mendix.modules.microflowengine.microflow.impl.MicroflowImpl.executeAfterBreakingIfNecessary(MicroflowImpl.java:193) at com.mendix.modules.microflowengine.microflow.impl.MicroflowImpl.executeAction(MicroflowImpl.java:148) at com.mendix.systemwideinterfaces.core.UserAction.execute(UserAction.java:53) at com.mendix.core.actionmanagement.CoreAction.doCall(CoreAction.java:291) at com.mendix.core.actionmanagement.CoreAction.call(CoreAction.java:276) at com.mendix.core.actionmanagement.ActionManager$1.execute(ActionManager.java:204) at com.mendix.util.classloading.Runner.doRunUsingClassLoaderOf(Runner.java:37) at com.mendix.core.actionmanagement.ActionManager.executeSync(ActionManager.java:199) at com.mendix.core.component.InternalCore.execute(InternalCore.java:263) at com.mendix.webui.actions.client.ExecuteAction.execute(ExecuteAction.java:135) at com.mendix.webui.requesthandling.ClientRequestHandler$$anonfun$handleRequest$1.apply$mcV$sp(ClientRequestHandler.scala:300) at com.mendix.webui.requesthandling.ClientRequestHandler$$anonfun$handleRequest$1.apply(ClientRequestHandler.scala:293) at com.mendix.webui.requesthandling.ClientRequestHandler$$anonfun$handleRequest$1.apply(ClientRequestHandler.scala:293) at com.mendix.core.session.Worker$$anonfun$receive$3$$anonfun$2$$anon$1.execute(ActionDispatching.scala:151) at com.mendix.util.classloading.Runner.doRunUsingClassLoaderOf(Runner.java:37) at com.mendix.core.session.Worker$$anonfun$receive$3$$anonfun$2.apply(ActionDispatching.scala:153) at scala.util.Try$.apply(Try.scala:191) at com.mendix.core.session.Worker$$anonfun$receive$3.applyOrElse(ActionDispatching.scala:147) at akka.actor.Actor$class.aroundReceive(Actor.scala:465) at com.mendix.core.session.Worker.aroundReceive(ActionDispatching.scala:140) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516) at akka.actor.ActorCell.invoke(ActorCell.scala:487) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238) at akka.dispatch.Mailbox.run(Mailbox.scala:220) at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393) at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) I couldn't find a documentation about this either.. Thanks,