null exception

[lucasjinreal]

java.lang.NullPointerException
	at java.base/java.util.concurrent.ConcurrentHashMap.putVal(ConcurrentHashMap.java:1011)
	at java.base/java.util.concurrent.ConcurrentHashMap.put(ConcurrentHashMap.java:1006)
	at java.base/java.util.Properties.put(Properties.java:1334)
	at com.db.MyBatis.getProperties(MyBatis.java:18)
	at com.db.MyBatis.getSession(MyBatis.java:29)
	at com.db.MyBatis.getUser(MyBatis.java:35)
	at com.chat.authorizers.authentication.connectAuthorizers.LoginAuthorizer.authorize(LoginAuthorizer.java:22)
	at com.chat.authorizers.authentication.MyAuthenticatorProvider.lambda$getAuthenticator$0(MyAuthenticatorProvider.java:49)
	at com.hivemq.extensions.auth.ConnectSimpleAuthTask.call(ConnectSimpleAuthTask.java:44)
	at com.hivemq.extensions.auth.ConnectSimpleAuthTask.call(ConnectSimpleAuthTask.java:28)
	at com.hivemq.extensions.auth.AbstractAuthTask.apply(AbstractAuthTask.java:55)
	at com.hivemq.extensions.auth.ConnectSimpleAuthTask.apply(ConnectSimpleAuthTask.java:28)
	at com.hivemq.extensions.auth.AbstractAuthTask.apply(AbstractAuthTask.java:31)
	at com.hivemq.extensions.executor.task.PluginTaskExecutor$PluginTaskExecutorRunnable.runInOutTask(PluginTaskExecutor.java:332)
	at com.hivemq.extensions.executor.task.PluginTaskExecutor$PluginTaskExecutorRunnable.runTask(PluginTaskExecutor.java:302)
	at com.hivemq.extensions.executor.task.PluginTaskExecutor$PluginTaskExecutorRunnable.executeTask(PluginTaskExecutor.java:251)
	at com.hivemq.extensions.executor.task.PluginTaskExecutor$PluginTaskExecutorRunnable.run(PluginTaskExecutor.java:164)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
	at java.base/java.lang.Thread.run(Thread.java:832)
2021-10-24 03:27:53,153 INFO  - nextExtensionOrDefault must not be called if authenticateSuccessfully, failAuthentication, continueAuthentication or nextExtensionOrDefault has already been called.
2021-10-24 03:27:53,156 INFO  - Client disconnected with id: demo_mqtt_pub 

I using a very simple python code test mqtt connection, just got above error. why??

import paho.mqtt.client as mqtt

def on_publish(client, userdata, mid):
    print("message ID ", mid)
    client.disconnect()

def on_connect(client, userdata, flags, rc):
    if rc == 0:
        client.publish("test", payload="hello world", qos=1)
    else:
        print("connection failed ", rc)

mqtt_client = mqtt.Client(client_id="demo_mqtt_pub", clean_session=False)
mqtt_client.on_connect = on_connect
mqtt_client.on_publish = on_publish
mqtt_client.username_pw_set(username="[email protected]",password="123")

mqtt_client.connect("127.0.0.1", 1883)
mqtt_client.loop_forever()