tauri-apps/tauri · error

Language {} not found. It must be one of {}

Error message

Language {} not found. It must be one of {}

What it means

Panic in the WiX MSI bundler. After running candle on the fragments, it iterates the configured languages (bundle > windows > wix > language) and looks each one up in the language map built from WiX's built-in locales plus configured WiX extensions; an unknown language aborts the build with the full list of valid keys.

Source

Thrown at crates/tauri-bundler/src/bundle/windows/msi/mod.rs:832

  // sign default extensions
  if settings.windows().can_sign() {
    for path in &fragment_extensions {
      try_sign(path, settings)?;
    }
  }

  for (path, extensions) in candle_inputs {
    for ext in &extensions {
      fragment_extensions.insert(ext.clone());
    }
    run_candle(settings, &wix_toolset_path, &output_path, path, extensions)?;
  }

  let mut output_paths = Vec::new();

  for (language, language_config) in configured_languages.0 {
    let language_metadata = language_map.get(&language).unwrap_or_else(|| {
      panic!(
        "Language {} not found. It must be one of {}",
        language,
        language_map
          .keys()
          .cloned()
          .collect::<Vec<String>>()
          .join(", ")
      )
    });

    let locale_contents = match language_config.locale_path {
      Some(p) => fs::read_to_string(p)?,
      None => format!(
        r#"<WixLocalization Culture="{}" xmlns="http://schemas.microsoft.com/wix/2006/localization"></WixLocalization>"#,
        language.to_lowercase(),
      ),
    };

View on GitHub (pinned to 52e4b6e71d)

Solutions

1. Use one of the language codes listed in the panic message, with hyphen separators (e.g. 'en-US')
2. For extension-backed languages, add the needed WiX extension to bundle > windows > wix > extensions and re-run
3. Remove or fix the offending entry in the wix language configuration (map or array form)

Example fix

// before (tauri.conf.json)
"bundle": { "windows": { "wix": { "language": "en_US" } } } // panic: not in map

// after
"bundle": { "windows": { "wix": { "language": "en-US" } } }

// keep MSI languages to a vetted allowlist with hyphenated codes
const ALLOWED = new Set(['en-US', 'de-DE', 'fr-FR', 'ja-JP', 'zh-CN']);
const langs = wixLanguageIsArray ? wixLanguage : Object.keys(wixLanguage);
langs.forEach((l) => { if (!ALLOWED.has(l)) throw new Error(`unsupported MSI language: ${l}`); });

When it happens

Trigger: Configuring an MSI language that is not in the map: typos such as 'en_US' instead of 'en-US' (underscore vs hyphen), unsupported locales, or locales that require a WiX extension (e.g. ar-SA) that was not added under wix > extensions.

Common situations: See trigger scenarios.

Related errors

• Failed to setup custom handlebar template
• Failed to setup handlebar template
• Failed to create locale file
• failed to extract merge module filename
• failed to convert merge module filename to string

AI-assisted analysis of tauri-apps/tauri@52e4b6e71d (2026-08-20). Data as JSON: /api/errors/43fa771c2e53979e. Report an issue: GitHub.