Hi all, I have an application in Mendix Studio Pro 10.18.4, I had to upgrade it to 10.21.0, I did that with the Upgrade Solution button, but after merging the changes and solving the conflicts I can't start my application because I get this error: java.lang.IllegalArgumentException: requirement failed: MicroflowActionRegistry does not contain class 'com.mendix.model.microflows.ModelNanoflowCallAction'. at scala.Predef$.require(Predef.scala:337) at com.mendix.modules.microflowengine.actions.impl.MicroflowActionRegistry.createMicroflowAction(MicroflowActionRegistry.scala:33) at com.mendix.modules.microflowengine.actions.impl.MicroflowActionBuilder.createMicroflowAction(MicroflowActionBuilder.scala:24) at com.mendix.modules.microflowengine.microflowstructure.MicroflowStructureFactory.processActivity(MicroflowStructureFactory.scala:196) at com.mendix.modules.microflowengine.microflowstructure.MicroflowStructureFactory.$anonfun$createMicroflowStructure$1(MicroflowStructureFactory.scala:47) at scala.collection.immutable.Vector.foreach(Vector.scala:2125) at com.mendix.modules.microflowengine.microflowstructure.MicroflowStructureFactory.createMicroflowStructure(MicroflowStructureFactory.scala:40) at com.mendix.modules.microflowengine.internal.MicroflowEngineModuleImpl.$anonfun$reload$2(MicroflowEngineModuleImpl.scala:38) at scala.collection.IterableOnceOps.foreach(IterableOnce.scala:619) at scala.collection.IterableOnceOps.foreach$(IterableOnce.scala:617) at scala.collection.AbstractIterable.foreach(Iterable.scala:935) at scala.collection.IterableOps$WithFilter.foreach(Iterable.scala:905) at com.mendix.modules.microflowengine.internal.MicroflowEngineModuleImpl.reload(MicroflowEngineModuleImpl.scala:37) at com.mendix.basis.impl.MxRuntimeImpl.initializeMicroflowEngine(MxRuntimeImpl.scala:900) at com.mendix.basis.impl.MxRuntimeImpl.doStart(MxRuntimeImpl.scala:855) at com.mendix.basis.impl.MxRuntimeImpl$Starting$.$anonfun$onEntry$17(MxRuntimeImpl.scala:537) at com.mendix.basis.impl.MxRuntimeImpl.com$mendix$basis$impl$MxRuntimeImpl$$onFailureTransitionTo(MxRuntimeImpl.scala:329) at com.mendix.basis.impl.MxRuntimeImpl$Starting$.onEntry(MxRuntimeImpl.scala:537) at com.mendix.basis.impl.MxRuntimeImpl.enter(MxRuntimeImpl.scala:324) at com.mendix.basis.impl.MxRuntimeImpl.com$mendix$basis$impl$MxRuntimeImpl$$transitionTo(MxRuntimeImpl.scala:315) at com.mendix.basis.impl.MxRuntimeImpl$Idle$.start(MxRuntimeImpl.scala:342) at com.mendix.basis.impl.MxRuntimeImpl.$anonfun$start$1(MxRuntimeImpl.scala:204) at scala.runtime.java8.JFunction0$mcZ$sp.apply(JFunction0$mcZ$sp.scala:17) at com.mendix.util.startupmeter.StartUpMeter.measure(StartUpMeter.scala:67) at com.mendix.basis.impl.MxRuntimeImpl.start(MxRuntimeImpl.scala:203) at com.mendix.m2ee.appcontainer.AppContainer.startRuntime(AppContainer.scala:363) at com.mendix.m2ee.appcontainer.actions.StartAction.execute(StartAction.scala:16) at com.mendix.m2ee.appcontainer.server.handler.HttpAdminHandlerBase.service(HttpAdminHandlerBase.java:131) at javax.servlet.http.HttpServlet.service(HttpServlet.java:590) at org.eclipse.jetty.ee8.servlet.ServletHolder.handle(ServletHolder.java:640) at org.eclipse.jetty.ee8.servlet.ServletHandler.doHandle(ServletHandler.java:456) at org.eclipse.jetty.ee8.nested.ScopedHandler.nextHandle(ScopedHandler.java:181) at org.eclipse.jetty.ee8.nested.ContextHandler.doHandle(ContextHandler.java:885) at org.eclipse.jetty.ee8.nested.ScopedHandler.nextScope(ScopedHandler.java:152) at org.eclipse.jetty.ee8.servlet.ServletHandler.doScope(ServletHandler.java:423) at org.eclipse.jetty.ee8.nested.ScopedHandler.nextScope(ScopedHandler.java:150) at org.eclipse.jetty.ee8.nested.ContextHandler.doScope(ContextHandler.java:830) at org.eclipse.jetty.ee8.nested.ScopedHandler.handle(ScopedHandler.java:117) at org.eclipse.jetty.ee8.nested.ContextHandler.handle(ContextHandler.java:1443) at org.eclipse.jetty.ee8.nested.HttpChannel$RequestDispatchable.dispatch(HttpChannel.java:1289) at org.eclipse.jetty.ee8.nested.HttpChannel.dispatch(HttpChannel.java:616) at org.eclipse.jetty.ee8.nested.HttpChannel.handle(HttpChannel.java:459) at org.eclipse.jetty.ee8.nested.ContextHandler$CoreContextHandler$CoreToNestedHandler.handle(ContextHandler.java:2450) at org.eclipse.jetty.server.handler.ContextHandler.handle(ContextHandler.java:1064) at org.eclipse.jetty.server.Server.handle(Server.java:182) at org.eclipse.jetty.server.internal.HttpChannelState$HandlerInvoker.run(HttpChannelState.java:662) at org.eclipse.jetty.server.internal.HttpConnection.onFillable(HttpConnection.java:416) at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:322) at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:99) at org.eclipse.jetty.io.SelectableChannelEndPoint$1.run(SelectableChannelEndPoint.java:53) at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.runTask(AdaptiveExecutionStrategy.java:480) at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.consumeTask(AdaptiveExecutionStrategy.java:443) at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.tryProduce(AdaptiveExecutionStrategy.java:293) at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.run(AdaptiveExecutionStrategy.java:201) at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:311) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:979) at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.doRunJob(QueuedThreadPool.java:1209) at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1164) at java.base/java.lang.Thread.run(Thread.java:1583) Do anybody know why is this happening and how can I solve it? Thanks! Gabriele