class org.antlr.v4.tool.Grammar cannot be cast to class org.antlr.v4.tool.LexerGrammar

[bjansen]

Not sure how it happened…

File file:///Users/…/grammars-v4/r/R.g4 isn't a lexer grammar

java.lang.ClassCastException: class org.antlr.v4.tool.Grammar cannot be cast to class org.antlr.v4.tool.LexerGrammar (org.antlr.v4.tool.Grammar and org.antlr.v4.tool.LexerGrammar are in unnamed module of loader com.intellij.ide.plugins.cl.PluginClassLoader @6468ca1e)
	at org.antlr.intellij.plugin.parsing.ParsingUtils.loadLexerGrammarFor(ParsingUtils.java:383)
	at org.antlr.intellij.plugin.parsing.ParsingUtils.loadGrammars(ParsingUtils.java:284)
	at org.antlr.intellij.plugin.ANTLRv4PluginController.updateGrammarObjectsFromFile_(ANTLRv4PluginController.java:422)
	at org.antlr.intellij.plugin.ANTLRv4PluginController.updateGrammarObjectsFromFile(ANTLRv4PluginController.java:400)
	at org.antlr.intellij.plugin.ANTLRv4PluginController.grammarFileSavedEvent(ANTLRv4PluginController.java:288)
	at org.antlr.intellij.plugin.ANTLRv4PluginController$MyVirtualFileAdapter.contentsChanged(ANTLRv4PluginController.java:630)
	at jdk.internal.reflect.GeneratedMethodAccessor91.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at com.intellij.util.EventDispatcher.dispatchVoidMethod(EventDispatcher.java:119)
	at com.intellij.util.EventDispatcher.lambda$createMulticaster$1(EventDispatcher.java:84)
	at jdk.proxy1/jdk.proxy1.$Proxy31.contentsChanged(Unknown Source)
	at com.intellij.openapi.vfs.impl.BulkVirtualFileListenerAdapter.fireAfter(BulkVirtualFileListenerAdapter.java:47)
	at com.intellij.openapi.vfs.impl.BulkVirtualFileListenerAdapter.after(BulkVirtualFileListenerAdapter.java:38)
	at com.intellij.util.messages.impl.MessageBusImplKt.invokeMethod(MessageBusImpl.kt:700)
	at com.intellij.util.messages.impl.MessageBusImplKt.invokeListener(MessageBusImpl.kt:660)
	at com.intellij.util.messages.impl.MessageBusImplKt.executeOrAddToQueue(MessageBusImpl.kt:492)
	at com.intellij.util.messages.impl.ToDirectChildrenMessagePublisher.publish$intellij_platform_core(CompositeMessageBus.kt:279)
	at com.intellij.util.messages.impl.MessagePublisher.invoke(MessageBusImpl.kt:449)
	at jdk.proxy1/jdk.proxy1.$Proxy63.after(Unknown Source)
	at com.intellij.openapi.vfs.newvfs.persistent.PersistentFSImpl.lambda$fireAfterEvents$20(PersistentFSImpl.java:1424)
	at com.intellij.openapi.vfs.newvfs.persistent.PersistentFSImpl.runSuppressing(PersistentFSImpl.java:1053)
	at com.intellij.openapi.vfs.newvfs.persistent.PersistentFSImpl.fireAfterEvents(PersistentFSImpl.java:1421)
	at com.intellij.openapi.vfs.newvfs.persistent.PersistentFSImpl.applyMultipleEvents(PersistentFSImpl.java:1398)
	at com.intellij.openapi.vfs.newvfs.persistent.PersistentFSImpl.processEventsImpl(PersistentFSImpl.java:1361)
	at com.intellij.openapi.vfs.newvfs.AsyncEventSupport.processEventsFromRefresh(AsyncEventSupport.java:153)
	at com.intellij.openapi.vfs.newvfs.RefreshSessionImpl.fireEventsInWriteAction(RefreshSessionImpl.java:240)
	at com.intellij.openapi.vfs.newvfs.RefreshSessionImpl.lambda$fireEvents$1(RefreshSessionImpl.java:222)
	at com.intellij.openapi.application.impl.ApplicationImpl.lambda$runEdtProgressWriteAction$6(ApplicationImpl.java:955)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$1(CoreProgressManager.java:192)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$executeProcessUnderProgress$12(CoreProgressManager.java:610)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:685)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computeUnderProgress(CoreProgressManager.java:641)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:609)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:78)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:179)
	at com.intellij.openapi.progress.util.PotemkinProgress.runInSwingThread(PotemkinProgress.java:150)
	at com.intellij.openapi.application.impl.ApplicationImpl.lambda$runEdtProgressWriteAction$7(ApplicationImpl.java:955)
	at com.intellij.openapi.application.impl.ApplicationImpl.runWriteActionWithClass(ApplicationImpl.java:963)
	at com.intellij.openapi.application.impl.ApplicationImpl.runEdtProgressWriteAction(ApplicationImpl.java:953)
	at com.intellij.openapi.application.impl.ApplicationImpl.runWriteActionWithNonCancellableProgressInDispatchThread(ApplicationImpl.java:936)
	at com.intellij.openapi.vfs.newvfs.RefreshSessionImpl.fireEvents(RefreshSessionImpl.java:218)
	at com.intellij.openapi.vfs.newvfs.RefreshQueueImpl.lambda$queueSession$2(RefreshQueueImpl.java:115)
	at com.intellij.openapi.application.impl.NonBlockingReadActionImpl$Submission.lambda$safeTransferToEdt$7(NonBlockingReadActionImpl.java:717)
	at com.intellij.openapi.application.TransactionGuardImpl.runWithWritingAllowed(TransactionGuardImpl.java:209)
	at com.intellij.openapi.application.TransactionGuardImpl.access$100(TransactionGuardImpl.java:22)
	at com.intellij.openapi.application.TransactionGuardImpl$1.run(TransactionGuardImpl.java:191)
	at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:843)
	at com.intellij.openapi.application.impl.ApplicationImpl$4.run(ApplicationImpl.java:463)
	at com.intellij.openapi.application.impl.RwLockHolder.runWithEnabledImplicitRead(RwLockHolder.kt:75)
	at com.intellij.openapi.application.impl.RwLockHolder.runWithImplicitRead(RwLockHolder.kt:67)
	at com.intellij.openapi.application.impl.ApplicationImpl.runWithImplicitRead(ApplicationImpl.java:1436)
	at com.intellij.openapi.application.impl.FlushQueue.doRun(FlushQueue.java:82)
	at com.intellij.openapi.application.impl.FlushQueue.runNextEvent(FlushQueue.java:124)
	at com.intellij.openapi.application.impl.FlushQueue.flushNow(FlushQueue.java:44)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:792)
	at java.desktop/java.awt.EventQueue$3.run(EventQueue.java:739)
	at java.desktop/java.awt.EventQueue$3.run(EventQueue.java:733)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:761)
	at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.kt:695)
	at com.intellij.ide.IdeEventQueue._dispatchEvent$lambda$12(IdeEventQueue.kt:589)
	at com.intellij.openapi.application.impl.RwLockHolder.runWithoutImplicitRead(RwLockHolder.kt:44)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.kt:589)
	at com.intellij.ide.IdeEventQueue.access$_dispatchEvent(IdeEventQueue.kt:72)
	at com.intellij.ide.IdeEventQueue$dispatchEvent$processEventRunnable$1$1$1.compute(IdeEventQueue.kt:355)
	at com.intellij.ide.IdeEventQueue$dispatchEvent$processEventRunnable$1$1$1.compute(IdeEventQueue.kt:354)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:793)
	at com.intellij.ide.IdeEventQueue$dispatchEvent$processEventRunnable$1$1.invoke(IdeEventQueue.kt:354)
	at com.intellij.ide.IdeEventQueue$dispatchEvent$processEventRunnable$1$1.invoke(IdeEventQueue.kt:349)
	at com.intellij.ide.IdeEventQueueKt.performActivity$lambda$1(IdeEventQueue.kt:1014)
	at com.intellij.openapi.application.TransactionGuardImpl.performActivity(TransactionGuardImpl.java:106)
	at com.intellij.ide.IdeEventQueueKt.performActivity(IdeEventQueue.kt:1014)
	at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$7(IdeEventQueue.kt:349)
	at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:848)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.kt:391)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:207)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:92)