NiFi instance disconnected

Issue:

2021-07-08 09:13:55,657 ERROR org.apache.nifi.controller.StandardFlowService: Failed to load flow from cluster due to: org.apache.nifi.controller.UninheritableFlowException: Failed to connect node to cluster because local flow is different than cluster flow.
org.apache.nifi.controller.UninheritableFlowException: Failed to connect node to cluster because local flow is different than cluster flow.
	at org.apache.nifi.controller.StandardFlowService.loadFromConnectionResponse(StandardFlowService.java:1026)
	at org.apache.nifi.controller.StandardFlowService.load(StandardFlowService.java:539)
	at org.apache.nifi.web.server.JettyServer.start(JettyServer.java:1043)
	at org.apache.nifi.NiFi.init(NiFi.java:158)
	at org.apache.nifi.NiFi.init(NiFi.java:72)
	at org.apache.nifi.NiFi.main(NiFi.java:301)
Caused by: org.apache.nifi.controller.UninheritableFlowException: Proposed configuration is not inheritable by the flow controller because of flow differences: Found difference in Flows:
Local Fingerprint:
			"type": ["null","string"]
		},
		{
			"name": "FILE_SIZE",
			"type": ["null","string"]
		}
	]
}bbb0a0dc-413c-36d1-8464-05c1dfc0d1e8NO_VALUENO_VALUENO_VERSION_CONTROL_INFORMATION0487043f-6db3-3707
Cluster Fingerprint:
			"type": ["null","string"]
		},
		{
			"name": "FILE_SIZE",
			"type": ["null","string"]
		}
	]
}9a1935a1-3e91-1a85-9189-b185f4419739NO_VALUENO_VALUENO_VERSION_CONTROL_INFORMATION03e4304b-2263-1e0c
	at org.apache.nifi.controller.StandardFlowSynchronizer.sync(StandardFlowSynchronizer.java:315)
	at org.apache.nifi.controller.FlowController.synchronize(FlowController.java:1408)
	at org.apache.nifi.persistence.StandardXMLFlowConfigurationDAO.load(StandardXMLFlowConfigurationDAO.java:88)
	at org.apache.nifi.controller.StandardFlowService.loadFromBytes(StandardFlowService.java:812)
	at org.apache.nifi.controller.StandardFlowService.loadFromConnectionResponse(StandardFlowService.java:1001)
	... 5 common frames omitted

Caused:

File "flow.xml.gz" is not sync with other nodes.

Resolution:

Copy file "flow.xml.gz" from other node then restart NiFi instance.