mongodb/node-mongodb-native · error · MongoCryptError

unidentifiable error in MongoCrypt - received an error statu

Error message

unidentifiable error in MongoCrypt - received an error status from `libmongocrypt` but received no error message.

What it means

Thrown by the libmongocrypt state machine when the native context enters the MONGOCRYPT_CTX_ERROR state but getStatus().message is empty. The driver has no human-readable text from libmongocrypt to relay, so it reports this generic fallback. It almost always indicates a bug in libmongocrypt, a version skew between mongodb-client-encryption and libmongocrypt, or a malformed KMS/data-key document that libmongocrypt rejected without setting an error string.

Source

Thrown at src/client-side-encryption/state_machine.ts:291

            throw new MongoCryptError(message);
          }
          result = finalizedContext;
          break;
        }

        default:
          throw new MongoCryptError(`Unknown state: ${getState()}`);
      }
    }

    if (getState() === MONGOCRYPT_CTX_ERROR || result == null) {
      const message = getStatus().message;
      if (!message) {
        debug(
          `unidentifiable error in MongoCrypt - received an error status from \`libmongocrypt\` but received no error message.`
        );
      }
      throw new MongoCryptError(
        message ??
          'unidentifiable error in MongoCrypt - received an error status from `libmongocrypt` but received no error message.'
      );
    }

    return result;
  }

  /**
   * Handles the request to the KMS service. Exposed for testing purposes. Do not directly invoke.
   * @param kmsContext - A C++ KMS context returned from the bindings
   * @returns A promise that resolves when the KMS reply has be fully parsed
   */
  async kmsRequest(
    request: MongoCryptKMSRequest,
    options?: { timeoutContext?: TimeoutContext } & Abortable
  ): Promise<void> {
    const parsedUrl = request.endpoint.split(':');

View on GitHub (pinned to 3366c21a63)

Solutions

1. Update mongodb-client-encryption (and thereby libmongocrypt) to the latest version compatible with this driver version.
2. Enable driver logging (MONGODB_DEBUG=true or set logger) to capture libmongocrypt status traces before the empty-message error.
3. Inspect the data key document(s) in the key vault collection for malformed fields, missing keyMaterial, or invalid masterKey.
4. Reproduce with a minimal CSFLE snippet and file a bug with the driver / mongodb-client-encryption including versions and the operation invoked.

Example fix

// before: mismatched versions
// "mongodb-client-encryption": "^2.x"

// after: align with the version matrix in the driver README
// "mongodb-client-encryption": "^6.x"  (matching driver major)

import { MongoCryptError } from 'mongodb';
function isUnidentifiableMongoCryptError(e: unknown): boolean {
  return e instanceof MongoCryptError && /unidentifiable error in MongoCrypt/.test(e.message);
}

try {
  await clientEncryption.createDataKey('aws', { masterKey: { region, key } });
} catch (err) {
  if (err instanceof MongoCryptError && /unidentifiable error/.test(err.message)) {
    // Likely a version mismatch or malformed data key; enable debug logging and re-run.
    process.env.MONGODB_DEBUG = 'true';
  }
  throw err;
}

When it happens

Trigger: In state_machine.ts execute() after the state loop ends in MONGOCRYPT_CTX_ERROR with no status message; can occur during createContext()/createDataKey()/encrypt()/decrypt() of CSFLE/ClientEncryption.

Common situations: Incompatible versions of mongodb-client-encryption native bindings and libmongocrypt; corrupted or schema-malformed data key documents; KMS provider object with unexpected fields; calling ClientEncryption APIs after the parent context was disposed; rare libmongocrypt bug where an error path didn't populate the message.

Related errors

• Unable to create collection: ${cause.message}
• Malformed JSON body in GET request.
• Unable to complete request.
• Malformed response body - missing field `access_token`.
• Malformed response body - missing field `expires_in`.

AI-assisted analysis of mongodb/node-mongodb-native@3366c21a63 (2026-08-04). Data as JSON: /data/errors/3930f263f933aa66.json. Report an issue: GitHub.