stanfordnlp/CoreNLP · error · RuntimeException

none of flags.useXXXChar2 are on

Error message

none of flags.useXXXChar2 are on

What it means

TagAffixDetector requires at least one char2 corpus flag (useCTBChar2 or usePKChar2) when useChPos-style POS detection is active. If none of the flags.useXXXChar2 flags are on, no dictionary paths can be chosen and RuntimeException('none of flags.useXXXChar2 are on') is thrown.

Solutions

  1. Set useCTBChar2=true or usePKChar2=true alongside useChPos in the properties
  2. Remove useChPos if you don't intend to use character-based POS features
  3. Verify the properties file actually enables exactly one supported char2 flag

Example fix

// before (Properties)
useChPos=true
// after (Properties)
useChPos=true
usePKChar2=true
Defensive patterns

Strategy: validation

Validate before calling

Properties p = /* props */;
boolean anyChar2 = Stream.of("useASBCChar2","useCTBChar2","useHKChar2","useMSRChar2","usePKChar2")
  .anyMatch(k -> Boolean.parseBoolean(p.getProperty(k, "false")));
if (Boolean.parseBoolean(p.getProperty("useChPos","false")) && !anyChar2) {
  p.setProperty("useCTBChar2", "true");
}

Try / catch

try {
  new TagAffixDetector(flags);
} catch (RuntimeException e) {
  if (e.getMessage().contains("useXXXChar2")) {
    flags.useCTBChar2 = true;
    new TagAffixDetector(flags);
  } else throw e;
}

Prevention

When it happens

Trigger: Constructing TagAffixDetector with useChPos=true (or the outer condition true) but useCTBChar2=false and usePKChar2=false (and other char2 flags off).

Common situations: Setting useChPos without setting the corpus char2 flag; properties files where the corpus flag was renamed or removed; users enabling POS-char features on an unsupported configuration.

Understand the failure class

Background: "--flag is required" and "must specify" CLI errors: how missing-required-flag validation works and how to fix it — this error's family across 20 libraries.

Related errors

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/a88315351ba4f974. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/wordseg/TagAffixDetector.java:43

    if ( ! corporaDict.isEmpty() && ! corporaDict.endsWith("/")) {
      corporaDict = corporaDict + '/';
    }

    String ccPath;
    String adPath;
    if (flags.useChPos || flags.useCTBChar2 || flags.usePKChar2) {
      // if we're using POS information, override the ccPath
      // For now we only have list for CTB and PK
      if (flags.useASBCChar2 || flags.useHKChar2 || flags.useMSRChar2) {
        throw new RuntimeException("only support settings for CTB and PK now.");
      } else if (flags.useCTBChar2) {
        ccPath = corporaDict+"dict/character_list";
        adPath = corporaDict+"dict/in.ctb";
      } else if (flags.usePKChar2) {
        ccPath = corporaDict+"dict/pos_open/character_list.pku.utf8";
        adPath = corporaDict+"dict/in.pk";
      } else {
        throw new RuntimeException("none of flags.useXXXChar2 are on");
      }
    } else {
      ccPath = corporaDict+"dict/pos_close/char.ctb.list";
      adPath = corporaDict+"dict/in.ctb";
    }
    if (VERBOSE) {
      logger.info("TagAffixDetector: useChPos=" + flags.useChPos +
              " | useCTBChar2=" + flags.useCTBChar2 + " | usePKChar2=" + flags.usePKChar2);
      logger.info("TagAffixDetector: building TagAffixDetector from " + ccPath + " and " + adPath);
    }
    cc = new CorpusChar(ccPath);
    aD = new AffixDictionary(adPath);
  }

  String checkDic(String t2, String c2 ) {
    if(cc.getTag(t2, c2).equals("1"))
      return "1";
    return "0";

View on GitHub (pinned to 1b7edd19c4)