eclipse-vertx/vert.x · error · IllegalStateException

Invalid index

Error message

Invalid index 

What it means

Deserialization guard in ReplyFailure.fromInt: the integer read from the wire (e.g. a clustered event bus reply header) is not one of the mapped codes 0-3 (TIMEOUT, NO_HANDLERS, RECIPIENT_FAILURE, ERROR). The message is a generic sentinel appended with the offending index; this signals a version mismatch or corrupted reply data.

Source

Thrown at vertx-core/src/main/java/io/vertx/core/eventbus/ReplyFailure.java:55

  RECIPIENT_FAILURE,

  /**
   * A fatal error occured while delivering the message. Do not retry to send.
   */
  ERROR;

  public static ReplyFailure fromInt(int i) {
    switch (i) {
      case 0:
        return TIMEOUT;
      case 1:
        return NO_HANDLERS;
      case 2:
        return RECIPIENT_FAILURE;
      case 3:
        return ERROR;
      default:
        throw new IllegalStateException("Invalid index " + i);
    }
  }

  public int toInt() {
    switch (this) {
      case TIMEOUT:
        return 0;
      case NO_HANDLERS:
        return 1;
      case RECIPIENT_FAILURE:
        return 2;
      case ERROR:
        return 3;
      default:
        throw new IllegalStateException("How did we get here?");
    }
  }
}

View on GitHub (pinned to fb308bd8c3)

Solutions

1. Ensure all cluster nodes run compatible Vert.x versions
2. Treat unknown codes as ERROR when consuming untrusted reply data

When it happens

Trigger: Thrown at vertx-core/src/main/java/io/vertx/core/eventbus/ReplyFailure.java:55 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of eclipse-vertx/vert.x@fb308bd8c3 (2026-09-06). Data as JSON: /api/errors/569e7b92f2a0197c. Report an issue: GitHub.