TypeError: can't access property "3.5", x is undefined

[ops-handler]

Error

can't access property "3.5", x is undefined

Stack trace

../app/javascript/components/Editor.tsx:90 in Editor_default
../node_modules/@sentry/react/src/errorboundary.tsx:101 in new ErrorBoundary
../node_modules/@tanstack/react-query/src/QueryClientProvider.tsx:29 in QueryClientProvider

Tracking Details

• Project: exercism-js
• Sentry: TypeError: can't access property "3.5", x is undefined
• Culprit: Editor_default(app/javascript/components/Editor)
• First seen: Aug 18, 2026