Opening a window whose target was removed from the registry (its tab stays open by design) and failing landed in the action menu with a "重试连接" row that indexed self.entries directly and raised KeyError, killing the popup with a traceback. Only offer the retry action for registered targets, degrade a stale retry row to a message, and keep the popup alive when a handler raises anything unexpected instead of dying with a traceback. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>