Switching between branches throws exception

[enikao]

In my "DetailsBack" example, I had master branch checked out. I changed some Dclare rules.
Then I checkout out working with force checkout option.

Declare didn't like that:

[1832496]  ERROR - smanager.tree.FeatureForestMap - Exception on firing featureStateChanged event
java.lang.AssertionError: EventsCollector was already configured to listen for changes in this model descriptor: r:20a227dc-6f8d-4f6b-8124-f964ef8ce2aa(Fine.rules)
        at jetbrains.mps.smodel.ModelsEventsCollector.startListeningToModel(ModelsEventsCollector.java:78)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceRegistry$MyEventsCollector.addListener(CurrentDifferenceRegistry.java:231)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceRegistry.addEventCollector(CurrentDifferenceRegistry.java:155)
        at jetbrains.mps.vcs.changesmanager.ChangesTracking.<init>(ChangesTracking.java:119)
        at jetbrains.mps.vcs.changesmanager.CurrentDifference.<init>(CurrentDifference.java:25)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceRegistry.getCurrentDifference(CurrentDifferenceRegistry.java:136)
        at jetbrains.mps.vcs.changesmanager.tree.TreeHighlighter$2.compute(TreeHighlighter.java:211)
        at jetbrains.mps.vcs.changesmanager.tree.TreeHighlighter$2.compute(TreeHighlighter.java:201)
        at jetbrains.mps.util.AbstractComputeRunnable.run(AbstractComputeRunnable.java:27)
        at jetbrains.mps.smodel.WorkbenchModelAccess.runReadAction(WorkbenchModelAccess.java:73)
        at jetbrains.mps.smodel.ModelAccessBase.runReadAction(ModelAccessBase.java:54)
        at jetbrains.mps.vcs.changesmanager.tree.TreeHighlighter.rehighlightNode(TreeHighlighter.java:229)
        at jetbrains.mps.vcs.changesmanager.tree.TreeHighlighter.rehighlightFeature(TreeHighlighter.java:248)
        at jetbrains.mps.vcs.changesmanager.tree.TreeHighlighter.rehighlightFeatureAndDescendants(TreeHighlighter.java:278)
        at jetbrains.mps.vcs.changesmanager.tree.TreeHighlighter$MyFeatureForestMapListener.featureStateChanged(TreeHighlighter.java:492)
        at jetbrains.mps.vcs.changesmanager.tree.FeatureForestMap.fireFeatureStateChanged(FeatureForestMap.java:127)
        at jetbrains.mps.vcs.changesmanager.tree.FeatureForestMap.removeKey(FeatureForestMap.java:79)
        at jetbrains.mps.vcs.changesmanager.tree.FeatureForestMapSupport$MyListener$2.visit(FeatureForestMapSupport.java:117)
        at jetbrains.mps.vcs.changesmanager.tree.FeatureForestMapSupport$MyListener$2.visit(FeatureForestMapSupport.java:115)
        at jetbrains.mps.internal.collections.runtime.IVisitor.invoke(IVisitor.java:12)
        at jetbrains.mps.internal.collections.runtime.IterableUtils.visitAll(IterableUtils.java:16)
        at jetbrains.mps.internal.collections.runtime.AbstractSequence.visitAll(AbstractSequence.java:80)
        at jetbrains.mps.vcs.changesmanager.tree.FeatureForestMapSupport$MyListener.changeRemoved(FeatureForestMapSupport.java:115)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceBroadcaster$2.invoke(CurrentDifferenceBroadcaster.java:54)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceBroadcaster$2.invoke(CurrentDifferenceBroadcaster.java:52)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceBroadcaster.fireEvent(CurrentDifferenceBroadcaster.java:33)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceBroadcaster.changeRemoved(CurrentDifferenceBroadcaster.java:52)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceBroadcaster$2.invoke(CurrentDifferenceBroadcaster.java:54)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceBroadcaster$2.invoke(CurrentDifferenceBroadcaster.java:52)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceBroadcaster.fireEvent(CurrentDifferenceBroadcaster.java:33)
        at jetbrains.mps.vcs.changesmanager.CurrentDifferenceBroadcaster.changeRemoved(CurrentDifferenceBroadcaster.java:52)
        at jetbrains.mps.vcs.changesmanager.CurrentDifference$1.visit(CurrentDifference.java:48)
        at jetbrains.mps.vcs.changesmanager.CurrentDifference$1.visit(CurrentDifference.java:46)
        at jetbrains.mps.internal.collections.runtime.IVisitor.invoke(IVisitor.java:12)
        at jetbrains.mps.internal.collections.runtime.IterableUtils.visitAll(IterableUtils.java:16)
        at jetbrains.mps.internal.collections.runtime.AbstractSequence.visitAll(AbstractSequence.java:80)
        at jetbrains.mps.vcs.changesmanager.CurrentDifference.removeChangeSet(CurrentDifference.java:46)
        at jetbrains.mps.vcs.changesmanager.ChangesTracking$2.run(ChangesTracking.java:186)
        at jetbrains.mps.smodel.ActionDispatcher.dispatch(ActionDispatcher.java:85)
        at jetbrains.mps.smodel.WorkbenchModelAccess.lambda$runReadAction$0(WorkbenchModelAccess.java:80)
        at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:907)
        at jetbrains.mps.smodel.WorkbenchModelAccess.runReadAction(WorkbenchModelAccess.java:77)
        at jetbrains.mps.smodel.ModelAccessBase.runReadAction(ModelAccessBase.java:54)
        at jetbrains.mps.vcs.changesmanager.ChangesTracking.update(ChangesTracking.java:168)
        at jetbrains.mps.vcs.changesmanager.CurrentDifference$4.run(CurrentDifference.java:110)
        at jetbrains.mps.vcs.changesmanager.SimpleCommandQueue$MyExecutorThread.run(SimpleCommandQueue.java:97)
[1832510]  ERROR -    jetbrains.mps.smodel.SModel - Model Fine.rules@repository: version for language DclareMPS not found. Using last version instead.
[1832680]   INFO - s.plugins.PluginLoaderRegistry - Unloading of 2 plugins took 0,000 s
[1832691]   INFO - s.plugins.PluginLoaderRegistry - Loading of 2 plugins took 0,008 s