org.springframework.messaging.MessageHandlingException: error occurred in message handler [envPublisher]; nested exception is org.springframework.messaging.MessagingException: Failed to connect; nested exception is MqttException (0)

at org.springframework.integration.support.utils.IntegrationUtils.wrapInHandlingExceptionIfNecessary(IntegrationUtils.java:184) ~[spring-integration-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:175) ~[spring-integration-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at com.etraffic.iot.protocol.config.EnvMessageSender.send(EnvMessageSender.java:45) [1iot-mqtt-service-5-environmental-sensor-1.0.jar:?]
at com.etraffic.iot.config.MqttMessageSender.send(MqttMessageSender.java:90) [1iot-mqtt-main-1.0.jar:?]
at com.etraffic.iot.config.MqttMessageSender.send(MqttMessageSender.java:53) [1iot-mqtt-main-1.0.jar:?]
at com.etraffic.iot.task.EnvSensorClockSynTask$ScheduleTask.run(EnvSensorClockSynTask.java:54) [1iot-mqtt-service-5-environmental-sensor-1.0.jar:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_181]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_181]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_181]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_181]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_181]

Caused by: org.springframework.messaging.MessagingException: Failed to connect; nested exception is MqttException (0)

at org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler.checkConnection(MqttPahoMessageHandler.java:180) ~[spring-integration-mqtt-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler.publish(MqttPahoMessageHandler.java:189) ~[spring-integration-mqtt-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.integration.mqtt.outbound.AbstractMqttMessageHandler.handleMessageInternal(AbstractMqttMessageHandler.java:267) ~[spring-integration-mqtt-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:158) ~[spring-integration-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
... 9 more

Caused by: org.eclipse.paho.client.mqttv3.MqttPersistenceException: MqttException

at org.eclipse.paho.client.mqttv3.persist.MqttDefaultFilePersistence.restoreBackups(MqttDefaultFilePersistence.java:276) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?]
at org.eclipse.paho.client.mqttv3.persist.MqttDefaultFilePersistence.open(MqttDefaultFilePersistence.java:126) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?]
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.<init>(MqttAsyncClient.java:481) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?]
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.<init>(MqttAsyncClient.java:328) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?]
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.<init>(MqttAsyncClient.java:323) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?]
at org.springframework.integration.mqtt.core.DefaultMqttPahoClientFactory.getAsyncClientInstance(DefaultMqttPahoClientFactory.java:181) ~[spring-integration-mqtt-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler.checkConnection(MqttPahoMessageHandler.java:170) ~[spring-integration-mqtt-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler.publish(MqttPahoMessageHandler.java:189) ~[spring-integration-mqtt-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.integration.mqtt.outbound.AbstractMqttMessageHandler.handleMessageInternal(AbstractMqttMessageHandler.java:267) ~[spring-integration-mqtt-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:158) ~[spring-integration-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
... 9 more