Search Head Clustering not working properly

[syazwani]

Hi,

HTTP 503 Service Unavailable -- {"messages":[{"type":"ERROR","text":"This node is not the captain of the search head cluster, and we could not determine the current captain. The cluster is either in the process of electing a new captain, or this member hasn't joined the pool"}]}

We received this error on one of the Search head cluster member. Is there any way to troubleshoot this? Please assist. Thankyou.