stanfordnlp/CoreNLP · error · IllegalArgumentException

Unknown model type " + modelType

Error message

Unknown model type " + modelType

What it means

After validating the -model property, ConvertModels.main dispatches on the Model enum; if the parsed modelType falls through all known branches it throws IllegalArgumentException('Unknown model type ' + modelType). This guards against enum values added to Model but not yet handled in main's switch/if chain.

Solutions

1. Use a model type supported by this ConvertModels build (SENTIMENT, DVPARSER, EMBEDDING, COREF, FASTCOREF)
2. Add a conversion branch for the new Model value in main
3. Rebuild/upgrade to a CoreNLP version whose ConvertModels handles the model type

Example fix

// before
java ... -model NEWTYPE -input m.gz -output m2.gz
// after
java ... -model COREF -input m.gz -output m2.gz  // use a handled type, or patch main() to support NEWTYPE

java.util.Set<String> handled = java.util.Set.of("SENTIMENT","DVPARSER","EMBEDDING","COREF","FASTCOREF");
if (!handled.contains(modelType)) {
  throw new IllegalArgumentException("model type " + modelType + " has no conversion branch");
}

try {
  ConvertModels.main(args);
} catch (IllegalArgumentException e) {
  if (e.getMessage().startsWith("Unknown model type")) {
    System.err.println("Model not supported by this ConvertModels build: " + e.getMessage());
    System.exit(3);
  }
  throw e;
}

When it happens

Trigger: Model enum contains a value with no conversion branch in main (e.g. a newly added model type), reaching the final else of main.

Common situations: Running a newer model enum value against an older ConvertModels version, or custom builds where Model was extended without updating main's dispatch.

Related errors

• Please specify -model, either SENTIMENT, DVPARSER…
• Someone didn't add a handler for a new docType.
• Arabic does not support feature type: " + feat.toString()
• CoNLLUOutputter: unknown dependencies type " +…
• Don't know anything about tagset

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/a79633d99d0f1fe6. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/neural/ConvertModels.java:467

        ObjectInputStream in = IOUtils.readStreamFromString(inputPath);
        NeuralCorefModel model = readCoref(in);
        in.close();
        IOUtils.writeObjectToFile(model, outputPath);
      }
    } else if (modelType == Model.FASTCOREF) {
      if (stage == Stage.OLD) {
        FastNeuralCorefModel model = ErasureUtils.uncheckedCast(IOUtils.readObjectFromURLOrClasspathOrFileSystem(inputPath));
        ObjectOutputStream out = IOUtils.writeStreamFromString(outputPath);
        writeFastCoref(model, out);
        out.close();
      } else {
        ObjectInputStream in = IOUtils.readStreamFromString(inputPath);
        FastNeuralCorefModel model = readFastCoref(in);
        in.close();
        IOUtils.writeObjectToFile(model, outputPath);
      }
    } else {
      throw new IllegalArgumentException("Unknown model type " + modelType);
    }
  }
}

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