---
title: "Language loading"
description: "Fix language authorization, availability, server rendering, and original-language fallback."
canonical_url: "https://docs.linguana.dev/docs/troubleshooting/catalog-runtime"
markdown_url: "https://docs.linguana.dev/docs/troubleshooting/catalog-runtime.md"
x_farming_labs_generated_preamble: true
---

# Language loading
URL: /docs/troubleshooting/catalog-runtime
LLM index: /llms.txt
Description: Fix language authorization, availability, server rendering, and original-language fallback.

# 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`

<ExpectedResult>
The page remains readable while diagnostics identify the language and optional message ID without leaking content.
</ExpectedResult>

## Next

Add the scenario to [Test your integration](/docs/automate/test-integration) and rehearse [publishing a language](/docs/use-linguana/publish-language) when a published language is the cause.

## Sitemap

See the full [sitemap](/sitemap.md) for all pages.
Docs-scoped sitemap: [/docs/sitemap.md](/docs/sitemap.md).
Well-known sitemap: [/.well-known/sitemap.md](/.well-known/sitemap.md).