Troubleshoot language loading

404 or access error

Confirm the project, environment, language, published version, API URL, and publishable key. A project token is not a browser key.

The language file is rejected

Do not render the response. Check that the project, environment, and language in the response match the request, then request it again.

The language does not change

setLocale changes when the language is the fallback, already loaded, or successfully fetched. Confirm it appears in availableLocales, then inspect ready and the language-loading diagnostic.

Hydration mismatch

Serialize the exact server-resolved locale and catalogs through LocaleHydrationState. Do not independently re-resolve the first client locale. When server remote loading fails, return source state rather than the requested unavailable locale.

The original language appears

This is the expected behavior when a language is missing or cannot be loaded. Inspect the diagnostics:

• missing-translation
• invalid-translation
• catalog-load-failed

Next

Add the scenario to Test your integration and rehearse publishing a language when a published language is the cause.