alibaba/nacos · error · IllegalArgumentException

Invalid protocolVersion: {protocolVersion}

Error message

Invalid protocolVersion: {protocolVersion}

What it means

Error "Invalid protocolVersion: {protocolVersion}" thrown in alibaba/nacos.

Source

Thrown at api/src/main/java/com/alibaba/nacos/api/ai/utils/AgentValidationUtils.java:148

     * @throws IllegalArgumentException when invalid
     */
    public static void validateProtocol(String protocol) {
        if (protocol == null || protocol.length() > MAX_PROTOCOL_LENGTH
            || !PROTOCOL_PATTERN.matcher(protocol).matches()) {
            throw new IllegalArgumentException("Invalid protocol: " + protocol);
        }
    }
    
    /**
     * Validate an optional protocol-version value when present.
     *
     * @param protocolVersion protocol-version value
     * @throws IllegalArgumentException when invalid
     */
    public static void validateProtocolVersion(String protocolVersion) {
        if (protocolVersion == null || protocolVersion.isEmpty()
            || protocolVersion.length() > MAX_PROTOCOL_VERSION_LENGTH) {
            throw new IllegalArgumentException("Invalid protocolVersion: " + protocolVersion);
        }
        validatePrintableAscii(protocolVersion, "protocolVersion");
    }
    
    /**
     * Validate a version label, including the server-managed {@code latest} label.
     *
     * @param label version label
     * @throws IllegalArgumentException when invalid
     */
    public static void validateLabel(String label) {
        if (label == null || label.length() > MAX_LABEL_LENGTH
            || !LABEL_PATTERN.matcher(label).matches()) {
            throw new IllegalArgumentException("Invalid label: " + label);
        }
    }
    
    /**

View on GitHub (pinned to 9b989acdf1)

Solutions

1. Correct the invalid value for protocolVersion validation to match the expected format or allowed set, then retry.

When it happens

Trigger: Thrown at api/src/main/java/com/alibaba/nacos/api/ai/utils/AgentValidationUtils.java:148 when the library encounters an invalid state.

Common situations: Validating an endpoint with an invalid protocolVersion value.

AI-assisted analysis of alibaba/nacos@9b989acdf1 (2026-08-14). Data as JSON: /api/errors/79575583f8b586e6. Report an issue: GitHub.