stanfordnlp/CoreNLP · error · IllegalStateException

Cannot run OpenIE without a parse tree!

Error message

Cannot run OpenIE without a parse tree!

What it means

annotateSentence() requires a dependency parse: it first tries EnhancedPlusPlusDependenciesAnnotation, then BasicDependenciesAnnotation. If both are absent it cannot build the SemanticGraph needed for relation extraction, so it throws an IllegalStateException. OpenIE is a downstream annotator that depends on a parsing annotator running first.

Solutions

  1. Add a dependency parser to the pipeline: annotators = "tokenize,ssplit,pos,lemma,depparse,natlog,openie".
  2. Verify the input annotations contain EnhancedPlusPlusDependenciesAnnotation (or BasicDependenciesAnnotation) before calling annotateSentence.
  3. If using 'parse' instead of 'depparse', ensure the parse output is converted to dependency annotations the annotator reads.

Example fix

// before
props.setProperty("annotators", "tokenize,ssplit,pos,lemma,openie");
// after
props.setProperty("annotators", "tokenize,ssplit,pos,lemma,depparse,natlog,openie");
Defensive patterns

Strategy: validation

Validate before calling

if (sentence.get(SemanticGraphCoreAnnotations.EnhancedPlusPlusDependenciesAnnotation.class) == null
    && sentence.get(SemanticGraphCoreAnnotations.BasicDependenciesAnnotation.class) == null) {
  throw new IllegalArgumentException("Run depparse (or parse) before OpenIE");
}

Try / catch

try {
  openie.annotate(sentence);
} catch (IllegalStateException e) {
  log.warn("Skipping sentence without dependency parse");
}

Prevention

When it happens

Trigger: Running the openie annotator in a StanfordCoreNLP pipeline without a parser (parse or depparse), or applying OpenIE to CoreMaps/Annotations that were never parsed.

Common situations: Pipeline configured as "tokenize,ssplit,pos,lemma,openie" (missing depparse); feeding pre-tokenized annotations that skipped parsing; using a custom annotator chain that drops dependency annotations.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/45b5601c78b26480. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/naturalli/OpenIE.java:470

  public void annotateSentence(CoreMap sentence, Map<CoreLabel, List<CoreLabel>> canonicalMentionMap) {
    List<CoreLabel> tokens = sentence.get(CoreAnnotations.TokensAnnotation.class);
    if (tokens.size() < 2) {

      // Short sentence. Skip annotating it.
      sentence.set(NaturalLogicAnnotations.RelationTriplesAnnotation.class, Collections.emptyList());
      if (!stripEntailments) {
        sentence.set(NaturalLogicAnnotations.EntailedSentencesAnnotation.class, Collections.emptySet());
      }

    } else {

      // Get the dependency tree
      SemanticGraph originalParse = sentence.get(SemanticGraphCoreAnnotations.EnhancedPlusPlusDependenciesAnnotation.class);
      if (originalParse == null) {
        originalParse = sentence.get(SemanticGraphCoreAnnotations.BasicDependenciesAnnotation.class);
      }
      if (originalParse == null) {
        throw new IllegalStateException("Cannot run OpenIE without a parse tree!");
      }
      // Clean the tree
      SemanticGraph parse = new SemanticGraph(originalParse);
      Util.cleanTree(parse, originalParse);

      // Resolve Coreference
      SemanticGraph canonicalizedParse = parse;
      if (resolveCoref && !canonicalMentionMap.isEmpty()) {
        canonicalizedParse = canonicalizeCoref(parse, canonicalMentionMap);
      }

      // Run OpenIE
      // (clauses)
      List<SentenceFragment> clauses = clausesInSentence(canonicalizedParse, true);  // note: uses coref-canonicalized parse
      // (entailment)
      Set<SentenceFragment> fragments = entailmentsFromClauses(clauses);
      // (segment)
      List<RelationTriple> extractions = segmenter.extract(parse, tokens);  // note: uses non-coref-canonicalized parse!

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