[BUG] JetBrains plugin: Assertion failed when removing selection listener on null editor

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Getting an assertion error in the Claude Code JetBrains plugin when switching between editor tabs or closing files.

What Should Happen?

When switching between editor tabs or closing a file, the plugin should cleanly remove the selection listener without throwing an assertion error.
No errors should appear in the IDE log during normal editor navigation.

Error Messages/Logs

java.lang.Throwable: Assertion failed: Failed to remove listener:                                                                                                    
  com.anthropic.code.plugin.mcp.notifications.NotificationManager$registerSelectionListener$selectionListener$1@6860caafrom editor: EditorImpl[null]                   
      at com.intellij.openapi.diagnostic.Logger.assertTrue(Logger.java:472)                                                                                            
      at com.intellij.openapi.editor.impl.SelectionModelImpl.removeSelectionListener(SelectionModelImpl.java:125)                                                      
      at com.anthropic.code.plugin.mcp.notifications.NotificationManager$registerSelectionListener$2.selectionChanged(NotificationManager.kt:92)                       
      at com.intellij.util.messages.impl.MessageBusImplKt.invokeMethod(MessageBusImpl.kt:820)                                                                          
      at com.intellij.util.messages.impl.MessageBusImplKt.invokeListener(MessageBusImpl.kt:764)                                                                        
      at com.intellij.util.messages.impl.MessageBusImplKt.deliverMessage(MessageBusImpl.kt:503)                                                                        
      at com.intellij.util.messages.impl.MessageBusImplKt.pumpWaiting(MessageBusImpl.kt:482)                                                                           
      at com.intellij.util.messages.impl.MessageBusImplKt.access$pumpWaiting(MessageBusImpl.kt:1)                                                                      
      at com.intellij.util.messages.impl.MessagePublisher.invoke(MessageBusImpl.kt:545)                                                                                
      at jdk.proxy2/jdk.proxy2.$Proxy141.selectionChanged(Unknown Source)                                                                                              
      at com.intellij.openapi.fileEditor.impl.FileEditorManagerImpl.fireSelectionChanged$lambda$1(FileEditorManagerImpl.kt:1833)                                       
      at com.intellij.openapi.application.CoroutinesKt.writeIntentReadAction$lambda$0(coroutines.kt:324)                                                               
      at com.intellij.openapi.application.impl.AppImplKt$rethrowCheckedExceptions$2.invoke(appImpl.kt:126)                                                             
      at com.intellij.platform.locking.impl.NestedLocksThreadingSupport.doRunWriteIntentReadAction(NestedLocksThreadingSupport.kt:736)                                 
      at com.intellij.platform.locking.impl.NestedLocksThreadingSupport.runPreventiveWriteIntentReadAction(NestedLocksThreadingSupport.kt:710)                         
      at com.intellij.platform.locking.impl.NestedLocksThreadingSupport.runWriteIntentReadAction(NestedLocksThreadingSupport.kt:664)                                   
      at com.intellij.openapi.application.impl.ApplicationImpl.runWriteIntentReadAction(ApplicationImpl.java:1185)                                                     
      at com.intellij.openapi.application.CoroutinesKt.writeIntentReadAction(coroutines.kt:324)                                                                        
      at com.intellij.openapi.fileEditor.impl.FileEditorManagerImpl.fireSelectionChanged(FileEditorManagerImpl.kt:1832)                                                
      at com.intellij.openapi.fileEditor.impl.FileEditorManagerImpl.access$fireSelectionChanged(FileEditorManagerImpl.kt:127)                                          
      at com.intellij.openapi.fileEditor.impl.FileEditorManagerImpl$2$1$1.invokeSuspend(FileEditorManagerImpl.kt:286)                                                  
      at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:34)                                                                        
      at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:100)                                                                                                  
      at com.intellij.openapi.application.impl.DispatchedRunnable.run(DispatchedRunnable.kt:42)                                                                        
      at com.intellij.openapi.application.TransactionGuardImpl.runWithWritingAllowed(TransactionGuardImpl.java:239)                                                    
      at com.intellij.openapi.application.TransactionGuardImpl.access$100(TransactionGuardImpl.java:25)                                                                
      at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:221)                                                                    
      at com.intellij.openapi.application.impl.NonBlockingFlushQueue.runNextEvent$lambda$1$1$0(NonBlockingFlushQueue.kt:334)                                           
      at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:901)                                                       
      at com.intellij.openapi.application.impl.NonBlockingFlushQueue.runNextEvent$lambda$1$1(NonBlockingFlushQueue.kt:333)                                             
      at com.intellij.concurrency.ThreadContext.resetThreadContext(threadContext.kt:294)                                                                               
      at com.intellij.openapi.application.impl.NonBlockingFlushQueue.runNextEvent$lambda$1(NonBlockingFlushQueue.kt:330)                                               
      at com.intellij.platform.locking.impl.NestedLocksThreadingSupport.tryRunWriteIntentReadAction(NestedLocksThreadingSupport.kt:689)                                
      at com.intellij.openapi.application.impl.NonBlockingFlushQueue.runNextEvent(NonBlockingFlushQueue.kt:326)                                                        
      at com.intellij.openapi.application.impl.NonBlockingFlushQueue.flushNow(NonBlockingFlushQueue.kt:305)                                                            
      at com.intellij.openapi.application.impl.NonBlockingFlushQueue.FLUSH_NOW$lambda$0(NonBlockingFlushQueue.kt:167)                                                  
      at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318)                                                                                
      at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:781)                                                                                       
      at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:728)                                                                                                   
      at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:722)                                                                                                   
      at java.base/java.security.AccessController.doPrivileged(AccessController.java:400)                                                                              
      at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)                                             
      at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:750)                                                                                           
      at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.kt:664)                                                                                     
      at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.kt:517)                                                                                           
      at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$0$0$0(IdeEventQueue.kt:333)                                                                               
      at com.intellij.ide.IdeEventQueueKt.performActivity$lambda$1(IdeEventQueue.kt:1065)                                                                              
      at com.intellij.openapi.application.TransactionGuardImpl.performActivity(TransactionGuardImpl.java:109)                                                          
      at com.intellij.ide.IdeEventQueueKt.performActivity(IdeEventQueue.kt:1065)                                                                                       
      at com.intellij.ide.IdeEventQueue.dispatchEvent$lambda$0(IdeEventQueue.kt:331)                                                                                   
      at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.kt:371)                                                                                            
      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)

Steps to Reproduce

1. Open multiple files in the IDE
2. Switch between tabs / close a file
3. Error appears in the IDE log

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

0.1.14 (beta)

Platform

Other

Operating System

macOS

Terminal/Shell

IntelliJ IDEA terminal

Additional Information

_No response_