Audit Write Failure. Attempt to write to audit log on node

I am seeing this check failures continuously from past 1 day , as I m in a process of upgrading from 5.1 CE to 6.0 CE I have added 6.0 built nodes into existing cluster yesterday , but due some issues I have removed those new 6.0 nodes from cluster but still I see this errors .
As this Community edition there i no Audit feature .
when there is no Audit feature , then what might be causing this?
Audit Write Failure. Attempt to write to audit log on node “couch1-2” was unsuccessfulmenelaus_web_alerts_srv 000ns_1@couch1-2 5:35:12 PM Tue Nov 26, 2019

Audit Write Failure. Attempt to write to audit log on node “couch1-1” was unsuccessfulmenelaus_web_alerts_srv 000ns_1@couch1-1 5:35:09 PM Tue Nov 26, 2019

Audit Write Failure. Attempt to write to audit log on node “couch1-2” was unsuccessful (repeated 14 times)menelaus_web_alerts_srv 000ns_1@couch1-2 5:35:09 PM Tue Nov 26, 2019

Audit Write Failure. Attempt to write to audit log on node “couch1-1” was unsuccessful (repeated 14 times)menelaus_web_alerts_srv 000ns_1@couch1-1 5:35:07 PM Tue Nov 26, 2019

Audit Write Failure. Attempt to write to audit log on node “couch1-4” was unsuccessfulmenelaus_web_alerts_srv 000ns_1@couch1-4 5:35:07 PM Tue Nov 26, 2019

Audit Write Failure. Attempt to write to audit log on node “couch1-4” was unsuccessful (repeated 14 times)menelaus_web_alerts_srv 000ns_1@couch1-4 5:35:07 PM Tue Nov 26, 2019

Audit Write Failure. Attempt to write to audit log on node “couch1-3” was unsuccessfulmenelaus_web_alerts_srv 000ns_1@couch1-3 5:34:59 PM Tue Nov 26, 2019

Can you let me know what might be wrong.