Let's say something like this is in the IBM MQ error log.

----- amqzfula.c : 3165 -------------------------------------------------------
12/06/2022 10:44:17 PM - Process(4696.851316) User(mqm) Program(amqrmppa)
                    Host(server1.example.com) Installation(Installation1)
                    VRMF(9.1.0.10) QMgr(MANAGER01)
                    Time(2022-12-07T04:44:17.799Z)
                    ArithInsert1(2) ArithInsert2(2035)
                    CommentInsert1(john.doe)
                    CommentInsert2(my.service.id)
                    CommentInsert3(john.doe)
                   
AMQ9557E: Queue Manager User ID initialization failed for 'john.doe'.

EXPLANATION:
The call to initialize the User ID 'john.doe' failed with CompCode 2 and Reason
2035. If an MQCSP block was used, the User ID in the MQCSP block was
'my.service.id'. If a userID flow was used, the User ID in the UID header was
'john.doe' and any CHLAUTH rules applied prior to user adoption were evaluated
case-sensitively against this value.
ACTION:
Correct the error and try again.
----- cmqxrsrv.c : 2298 -------------------------------------------------------

This can occur when 

• MQConstants.USE_MQCSP_AUTHENTICATION_PROPERTY is set to false
• JmsConstants.USER_AUTHENTICATION_MQCSP is set to false
• System property com.ibm.mq.cfg.jmqi.useMQCSPauthentication is set to false

For example, here is an example Java class with MQConstants.USE_MQCSP_AUTHENTICATION_PROPERTY set to false.

import java.util.Hashtable;
import com.ibm.mq.MQException;
import com.ibm.mq.MQQueueManager;
import com.ibm.mq.constants.MQConstants;
public class Main {

  private static final String HOST       = "your ibm mq server or cluster hostname";
  private static final String QMGR       = "your ibm mq queue_manager";
  private static final String CHANNEL    = "your ibm mq channel";
  private static final String USERNAME   = "your ibm mq username";
  private static final String myPASSWORD = "your ibm mq password";
  private static final int PORT          = your ibm mq queue manager port;

  public static void main(String[] args) throws MQException {

    Hashtable<String, Object> properties = new Hashtable<String, Object>();
    properties.put(MQConstants.HOST_NAME_PROPERTY, HOST);
    properties.put(MQConstants.PORT_PROPERTY, PORT); 
    properties.put(MQConstants.CHANNEL_PROPERTY, CHANNEL); 
    properties.put(MQConstants.USER_ID_PROPERTY, USERNAME);
    properties.put(MQConstants.PASSWORD_PROPERTY, myPASSWORD);
    properties.put(MQConstants.USE_MQCSP_AUTHENTICATION_PROPERTY, false);

    try {
      MQQueueManager queueManagerConnection = new MQQueueManager("MANAGER01", properties);
      if (queueManagerConnection.isConnected()) {
        System.out.println("Successfully connected to CHANNEL01");
      }
      else {
        System.out.println("Failed to connect to CHANNEL01");
      }
      System.out.println(queueManagerConnection);
      queueManagerConnection.disconnect();
      System.out.println("Successfully disconnected from queue manager MANAGER01");
    } catch (MQException e) {
      e.printStackTrace();
    }
  }
}