elastic/elasticsearch · error · IllegalArgumentException

invalid value [{}] must be one of [true,false,limited]

Error message

invalid value [{}] must be one of [true,false,limited]

What it means

CompilerSettings.RegexEnabled.parse accepts exactly three lowercase string values for 'script.painless.regex.enabled': 'true', 'false', 'limited'. Unlike enum valueOf (which needs uppercase), this parser does a manual string compare and throws IllegalArgumentException listing the allowed set for any other input, including 'TRUE', 'False', 'on', 'off', 'yes', 'no', or typos.

Source

Thrown at modules/lang-painless/src/main/java/org/elasticsearch/painless/CompilerSettings.java:274

        final String value;

        RegexEnabled(String value) {
            this.value = value;
        }

        /**
         * Parse string value, necessary because `valueOf` would require strings to be upper case.
         */
        public static RegexEnabled parse(String value) {
            if (TRUE.value.equals(value)) {
                return TRUE;
            } else if (FALSE.value.equals(value)) {
                return FALSE;
            } else if (LIMITED.value.equals(value)) {
                return LIMITED;
            }
            throw new IllegalArgumentException(
                "invalid value [" + value + "] must be one of [" + TRUE.value + "," + FALSE.value + "," + LIMITED.value + "]"
            );
        }
    }
}

View on GitHub (pinned to db6a809a66)

Solutions

1. Use one of the exact lowercase literals: 'true', 'false', or 'limited'.
2. In YAML, quote the value to prevent implicit type coercion: script.painless.regex.enabled: "limited".
3. If applying via API, ensure the JSON value is a string of one of the three allowed literals.

Example fix

// before
script.painless.regex.enabled: TRUE
// after
script.painless.regex.enabled: "limited"

function validateRegexEnabled(v) {
  const allowed = ['true','false','limited'];
  if (!allowed.includes(String(v).toLowerCase()) || String(v) !== String(v).toLowerCase()) {
    throw new Error(`script.painless.regex.enabled must be one of ${allowed.join(',')} (lowercase)`);
  }
  return v;
}

When it happens

Trigger: Setting script.painless.regex.enabled to anything other than the literal strings 'true', 'false', or 'limited' — e.g. uppercase 'TRUE', 'enabled', '1', 'on', or a typo like 'limitted'.

Common situations: Porting a setting from another tool that accepts 'on'/'off' or uppercase booleans. YAML auto-conversion turning the value into a boolean type rather than the expected lowercase string. Copy-paste typos.

Related errors

• failed to parse value [{}] for setting [{}], must be [-1b] (
• [painless.regex.enabled] can only be set on node startup.
• [painless.regex.limit-factor] can only be set on node startu
• invalid dot validation exception pattern: [{}]
• Unrecognized compile-time parameter(s): {}

AI-assisted analysis of elastic/elasticsearch@db6a809a66 (2026-08-12). Data as JSON: /api/errors/bddfad80f1812ac3. Report an issue: GitHub.