Indexer Clustering: One or more replicated indexes may not be fully searchable. Some search results may be incomplete or duplicated as we try to fix up your cluster. For more information, check the cluster manager page on the master - splunkd URI: https://clustermaster:8089.
The error gets cleared when the cluster restores back to its normal state. Go to the master page on the cluster master and check for any pending fix up tasks. Monitor the fix up tasks and the count should gradually decrease if there are no issues. If not, check for the "reason" next to the fix up tasks that gives additional information.