java.lang.IllegalStateException: @NotNull method com/intellij/openapi/fileEditor/impl/FileEditorManagerImpl.openFileImpl2 must not return null
	at com.intellij.openapi.fileEditor.impl.FileEditorManagerImpl.openFileImpl2(FileEditorManagerImpl.java)
	at com.intellij.openapi.fileEditor.impl.FileEditorManagerImpl.a(FileEditorManagerImpl.java:342)
	at com.intellij.openapi.fileEditor.impl.FileEditorManagerImpl.openFileWithProviders(FileEditorManagerImpl.java:332)
	at com.intellij.openapi.fileEditor.ex.FileEditorManagerEx.openFile(FileEditorManagerEx.java:1)
	at org.jetbrains.plugins.grails.editor.EditorDecorator$2.actionPerformed(EditorDecorator.java:300)
	at javax.swing.JComboBox.fireActionEvent(JComboBox.java:1242)
	at javax.swing.JComboBox.contentsChanged(JComboBox.java:1313)
	at javax.swing.AbstractListModel.fireContentsChanged(AbstractListModel.java:100)
	at javax.swing.DefaultComboBoxModel.setSelectedItem(DefaultComboBoxModel.java:88)
	at javax.swing.DefaultComboBoxModel.removeElementAt(DefaultComboBoxModel.java:143)
	at javax.swing.DefaultComboBoxModel.removeElement(DefaultComboBoxModel.java:156)
	at org.jetbrains.plugins.grails.editor.EditorDecorator$1.removeFile(EditorDecorator.java:285)
	at org.jetbrains.plugins.grails.editor.EditorDecorator$1.beforeFileDeletion(EditorDecorator.java:280)
	at sun.reflect.GeneratedMethodAccessor64.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at com.intellij.util.PendingEventDispatcher.a(PendingEventDispatcher.java:73)
	at com.intellij.util.PendingEventDispatcher.a(PendingEventDispatcher.java:49)
	at com.intellij.util.PendingEventDispatcher.access$100(PendingEventDispatcher.java:54)
	at com.intellij.util.PendingEventDispatcher$1.invoke(PendingEventDispatcher.java:7)
	at $Proxy10.beforeFileDeletion(Unknown Source)
	at com.intellij.openapi.vfs.impl.VirtualFileManagerImpl.b(VirtualFileManagerImpl.java:154)
	at com.intellij.openapi.vfs.impl.VirtualFileManagerImpl.access$100(VirtualFileManagerImpl.java:128)
	at com.intellij.openapi.vfs.impl.VirtualFileManagerImpl$1.before(VirtualFileManagerImpl.java:3)
	at sun.reflect.GeneratedMethodAccessor38.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at com.intellij.util.messages.impl.MessageBusConnectionImpl.deliverMessage(MessageBusConnectionImpl.java:101)
	at com.intellij.util.messages.impl.MessageBusImpl.pumpMessages(MessageBusImpl.java:170)
	at com.intellij.util.messages.impl.MessageBusImpl.sendMessage(MessageBusImpl.java:162)
	at com.intellij.util.messages.impl.MessageBusImpl.access$000(MessageBusImpl.java:36)
	at com.intellij.util.messages.impl.MessageBusImpl$2.invoke(MessageBusImpl.java:102)
	at $Proxy52.before(Unknown Source)
	at com.intellij.openapi.vfs.newvfs.persistent.PersistentFS.processEvents(PersistentFS.java:8)
	at com.intellij.openapi.vfs.newvfs.RefreshSessionImpl.fireEvents(RefreshSessionImpl.java:3)
	at com.intellij.openapi.vfs.newvfs.RefreshQueueImpl$2$1$1.run(RefreshQueueImpl.java:3)
	at com.intellij.openapi.application.impl.ApplicationImpl.runWriteAction(ApplicationImpl.java:98)
	at com.intellij.openapi.vfs.newvfs.RefreshQueueImpl$2$1.run(RefreshQueueImpl.java:4)
	at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.run(LaterInvocator.java:19)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
	at com.intellij.ide.IdeEventQueue.c(IdeEventQueue.java:131)
	at com.intellij.ide.IdeEventQueue.b(IdeEventQueue.java:132)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:136)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)