languagetool-org/languagetool · error · RuntimeException

Invalid line in , expected 'RULE_ID,float_value[,...]':

Error message

Invalid line in , expected 'RULE_ID,float_value[,...]':

What it means

Confidence map lines must contain at least two columns ('RULE_ID,float_value[,...]'). If a non-empty line yields fewer than two tab-separated parts, load throws a RuntimeException naming the file and the line.

Source

Thrown at languagetool-server/src/main/java/org/languagetool/server/ConfidenceMapLoader.java:67

      if (!Paths.get(fileName).toFile().exists()) {
        continue;
      }
      List<String> lines = Files.readAllLines(Paths.get(fileName), UTF_8);
      for (String line : lines) {
        if (line.startsWith("#")) {
          continue;
        }
        String[] parts = line.split(",");
        if (parts.length >= 2) {   // there might be more columns for better debugging, but we don't use them here
          try {
            float confidence = Float.parseFloat(parts[1]);
            confMap.put(new ConfidenceKey(lang, parts[0]), confidence);
            loadCount++;
          } catch (NumberFormatException e) {
            throw new RuntimeException("Invalid confidence float value in " + fileName + ", expected 'RULE_ID,float_value[,...]': " + line);
          }
        } else {
          throw new RuntimeException("Invalid line in " + fileName + ", expected 'RULE_ID,float_value[,...]': " + line);
        }
      }
      logger.info("Loaded " + loadCount + " mappings for " + lang + " from confidence map for rules from " + fileName);
    }
    if (confMap.size() == 0) {
      throw new RuntimeException("No confidence values could be loaded for " + filePattern +
        " -- please check there are actually files that match this pattern");
    }
    return confMap;
  }

}

View on GitHub (pinned to 2e990059ce)

Solutions

  1. Give every line a second, tab-separated float column: 'RULE_ID<tab>0.8'.
  2. Check that fields are separated by tabs, not commas or spaces.
  3. Delete header, comment, or empty lines that do not match the format.
  4. Verify which file the message names and fix that language's file.

Example fix

// before
MY_RULE
// after
MY_RULE	0.8
Defensive patterns

Strategy: validation

Validate before calling

for (const line of lines) {
  if (line.split('\t').length < 2) throw new Error('Line needs RULE_ID and float value: ' + line);
}

Type guard

function hasTwoColumns(line) { return line.split('\t').length >= 2; }

Try / catch

try {
  Map<ConfidenceKey,Float> map = new ConfidenceMapLoader().load(filePattern);
} catch (RuntimeException e) {
  logger.error("Confidence map line invalid: " + e.getMessage());
}

Prevention

When it happens

Trigger: A confidence file contains a line with only a rule ID ('MY_RULE'), a blank-ish line, or a line using the wrong separator (space/comma instead of tab) so no second column is found.

Common situations: Manually edited files missing the value column; exporting CSV instead of the tab-separated format the loader expects; trailing header lines left in the file.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

AI-assisted analysis of languagetool-org/languagetool@2e990059ce (2026-09-06). Data as JSON: /api/errors/8de569e818d22906. Report an issue: GitHub.