languagetool-org/languagetool · error · RuntimeException

LanguageModel directory not found or is not a directory:

Error message

LanguageModel directory not found or is not a directory: 

What it means

setLanguageModelDirectory configures the n-gram LanguageModel directory used for better suggestions (e.g. for English/German). A RuntimeException is thrown when the supplied path does not exist or is a file rather than a directory.

Source

Thrown at languagetool-server/src/main/java/org/languagetool/server/HTTPServerConfig.java:561

          throw new IllegalArgumentException("dictionary file does not exist or is not a file: '" + dictPath + "'");
        }
        ServerTools.print("Adding dynamic spell checker language " + name + ", code: " + code + ", dictionary: " + dictPath);
        Language lang = Languages.addLanguage(name, code, new File(dictPath));
        // better fail early in case of misconfiguration, so use the language now:
        if (!new File(lang.getCommonWordsPath()).exists()) {
          throw new IllegalArgumentException("Common words path not found: '" + lang.getCommonWordsPath() + "'");
        }
        JLanguageTool lt = new JLanguageTool(lang);
        lt.check("test");
      }
    }
  }

  public void setLanguageModelDirectory(String langModelDir) {
    SuggestionsOrdererConfig.setNgramsPath(langModelDir);
    languageModelDir = new File(langModelDir);
    if (!languageModelDir.exists() || !languageModelDir.isDirectory()) {
      throw new RuntimeException("LanguageModel directory not found or is not a directory: " + languageModelDir);
    }
  }

  void setFasttextPaths(String fasttextModelPath, String fasttextBinaryPath) {
    fasttextModel = new File(fasttextModelPath);
    fasttextBinary = new File(fasttextBinaryPath);
    if (!fasttextModel.exists() || fasttextModel.isDirectory()) {
      throw new RuntimeException("Fasttext model path not valid (file doesn't exist or is a directory): " + fasttextModelPath);
    }
    if (!fasttextBinary.exists() || fasttextBinary.isDirectory() || !fasttextBinary.canExecute()) {
      throw new RuntimeException("Fasttext binary path not valid (file doesn't exist, is a directory or not executable): " + fasttextBinaryPath);
    }
  }

  /*
   * @param verbose if true, the text to be checked will be displayed in case of exceptions
   */
  public boolean isVerbose() {

View on GitHub (pinned to 2e990059ce)

Solutions

1. Download and unzip the n-grams data for the language and pass the extracted directory path
2. Verify with `ls -ld <path>` that the path exists and is a directory
3. Fix the --languageModel argument or config property to the correct directory

Example fix

// before
--languageModel /opt/ngrams-en.zip
// after
--languageModel /opt/ngrams-en

File dir = new File(langModelDir);
if (!dir.isDirectory())
  throw new IllegalStateException("LanguageModel dir missing: " + langModelDir);

try {
  config.setLanguageModelDir(modelDir);
} catch (RuntimeException e) {
  LOG.error("Bad languageModel dir: {}", e.getMessage());
}

When it happens

Trigger: Calling setLanguageModelDirectory(path) (directly or via the --languageModel server option) with a path that is absent on disk or points to a regular file.

Common situations: Forgetting to download/extract the n-grams dataset before starting the server, pointing at the zip archive instead of the extracted directory, or a typo in the path.

Related errors

• dictionary file does not exist or is not a file: ''
• Common words path not found: ''
• Fasttext model path not valid (file doesn't exist or is a di
• Fasttext binary path not valid (file doesn't exist, is a dir
• <dir.getAbsolutePath()> is not a directory, cannot use recur

AI-assisted analysis of languagetool-org/languagetool@2e990059ce (2026-09-06). Data as JSON: /api/errors/306b887bc3b19c16. Report an issue: GitHub.