Error after updating the MPS-Core plugin

Hi,

we are using mps as intellij plugin. For this we use the mps-core plugin (version 3.3) and extended the class FilePerRootDataSource to be able to open our schemas by override the method getFile.

. 

But now we updated to the latest version of the plugins (2017.3) and this class is final, so we cannot extend. So I changed to FolderDataSource but give me the following error

java.lang.IllegalArgumentException: Argument for @NotNull parameter 'virtualFile' of com/intellij/psi/impl/file/impl/FileManagerImpl.setViewProvider must not be null
at com.intellij.psi.impl.file.impl.FileManagerImpl.$$$reportNull$$$0(FileManagerImpl.java)
at com.intellij.psi.impl.file.impl.FileManagerImpl.setViewProvider(FileManagerImpl.java)
at jetbrains.mps.idea.core.psi.impl.MPSPsiModel.reload(MPSPsiModel.java:389)
at jetbrains.mps.idea.core.psi.impl.MPSPsiProvider$2$1.reload(MPSPsiProvider.java:256)
at jetbrains.mps.idea.core.psi.impl.events.SModelEventProcessor.processAffected(SModelEventProcessor.java:65)
at jetbrains.mps.idea.core.psi.impl.events.SModelEventProcessor.process(SModelEventProcessor.java:52)
at jetbrains.mps.idea.core.psi.impl.MPSPsiProvider$1.lambda$eventsHappenedInCommand$0(MPSPsiProvider.java:99)
at jetbrains.mps.idea.core.psi.impl.MPSPsiProvider$1.eventsHappenedInCommand(MPSPsiProvider.java:102)
at jetbrains.mps.smodel.GlobalSModelEventsManager$MyEventsCollector.eventsHappened(GlobalSModelEventsManager.java:134)
at jetbrains.mps.smodel.ModelsEventsCollector.lambda$flush$0(ModelsEventsCollector.java:93)
at jetbrains.mps.smodel.WorkbenchModelAccess.runWriteAction(WorkbenchModelAccess.java:97)
at jetbrains.mps.smodel.ModelsEventsCollector.flush(ModelsEventsCollector.java:93)
at jetbrains.mps.smodel.ModelsEventsCollector$MyCommandAdapter.commandFinished(ModelsEventsCollector.java:141)
at jetbrains.mps.smodel.WorkbenchModelAccess.onCommandFinished(WorkbenchModelAccess.java:408)
at jetbrains.mps.smodel.WorkbenchModelAccess.decCommandLevel(WorkbenchModelAccess.java:365)
at jetbrains.mps.smodel.WorkbenchModelAccess.access$200(WorkbenchModelAccess.java:49)
at jetbrains.mps.smodel.WorkbenchModelAccess$CommandRunnable.lambda$run$0(WorkbenchModelAccess.java:451)
at jetbrains.mps.smodel.WorkbenchModelAccess.runWriteAction(WorkbenchModelAccess.java:97)
at jetbrains.mps.smodel.WorkbenchModelAccess$CommandRunnable.run(WorkbenchModelAccess.java:446)
at com.intellij.openapi.command.impl.CoreCommandProcessor.executeCommand(CoreCommandProcessor.java:149)
at com.intellij.openapi.command.impl.CoreCommandProcessor.executeCommand(CoreCommandProcessor.java:109)
at com.intellij.openapi.command.impl.CoreCommandProcessor.executeCommand(CoreCommandProcessor.java:99)
at jetbrains.mps.smodel.WorkbenchModelAccess.runWriteActionInCommand(WorkbenchModelAccess.java:311)
at jetbrains.mps.smodel.WorkbenchModelAccess.executeCommand(WorkbenchModelAccess.java:307)
at jetbrains.mps.project.ProjectModelAccess.executeCommand(ProjectModelAccess.java:43)
at pt.i2s.ibml.navigation.I2SNavigationSupport.openRootNode(I2SNavigationSupport.java:46)
at pt.i2s.ibml.actions.IbmlActions.lambda$openRulesetInternal$4(IbmlActions.java:98)
at jetbrains.mps.smodel.WorkbenchModelAccess.lambda$tryWrite$6(WorkbenchModelAccess.java:199)
at jetbrains.mps.util.ComputeRunnable.compute(ComputeRunnable.java:32)
at jetbrains.mps.util.AbstractComputeRunnable.run(AbstractComputeRunnable.java:27)
at jetbrains.mps.smodel.WriteActionDispatcher.run(WriteActionDispatcher.java:39)
at jetbrains.mps.smodel.WriteActionDispatcher.compute(WriteActionDispatcher.java:49)
at jetbrains.mps.smodel.WorkbenchModelAccess.lambda$tryWrite$7(WorkbenchModelAccess.java:218)
at jetbrains.mps.util.ComputeRunnable.compute(ComputeRunnable.java:32)
at jetbrains.mps.util.AbstractComputeRunnable.run(AbstractComputeRunnable.java:27)
at jetbrains.mps.smodel.TryRunPlatformWriteHelper$TryWriteActionRunnable.lambda$tryWrite$0(TryRunPlatformWriteHelper.java:142)
at com.intellij.openapi.application.impl.ApplicationImpl.runWriteAction(ApplicationImpl.java:1004)
at jetbrains.mps.smodel.TryRunPlatformWriteHelper$TryWriteActionRunnable.tryWrite(TryRunPlatformWriteHelper.java:140)
at jetbrains.mps.smodel.TryRunPlatformWriteHelper.tryWrite(TryRunPlatformWriteHelper.java:121)
at jetbrains.mps.smodel.WorkbenchModelAccess.tryWrite(WorkbenchModelAccess.java:236)
at jetbrains.mps.smodel.WorkbenchModelAccess.tryWrite(WorkbenchModelAccess.java:202)
at jetbrains.mps.smodel.WorkbenchModelAccess.lambda$runWriteInEDT$3(WorkbenchModelAccess.java:151)
at jetbrains.mps.smodel.EDTExecutorInternal.tryToRunTopTask(EDTExecutorInternal.java:204)
at jetbrains.mps.smodel.EDTExecutorInternal.flushNTasks(EDTExecutorInternal.java:167)
at jetbrains.mps.smodel.EDTExecutorInternal.doFlush(EDTExecutorInternal.java:141)
at jetbrains.mps.smodel.EDTExecutorInternal.flushTasksQueue(EDTExecutorInternal.java:129)
at com.intellij.openapi.application.TransactionGuardImpl.runSyncTransaction(TransactionGuardImpl.java:88)
at com.intellij.openapi.application.TransactionGuardImpl.lambda$submitTransaction$1(TransactionGuardImpl.java:111)
at com.intellij.openapi.application.TransactionGuardImpl.submitTransaction(TransactionGuardImpl.java:120)
at com.intellij.openapi.application.TransactionGuardImpl.lambda$submitTransactionLater$4(TransactionGuardImpl.java:271)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.runNextEvent(LaterInvocator.java:424)
at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.run(LaterInvocator.java:407)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:822)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:650)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:366)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
2018-06-26 08:28:31,387 [ 167817] INFO - terceptor.LoggingInInterceptor - Inbound Message

When I try to open on of my schemas because of 

MPSProject component = project.getComponent(MPSProject.class);
ModelAccess modelAccess = component.getRepository().getModelAccess();
modelAccess.executeCommand

The problem is in MPSPsiModel reload method that is initializing the MPSPsiRootNode without mySeparateFile (virtual file). Before the update I could extend from FilePerRootDataSource so MPSPsiRootNode could be initialize with virtual file, but now I cannot.

How can I do this?

Thanks