ElasticSearch username as Null

@warkolm and others . Any inputs please. Collection rebuild for indexing fails with below error on Oracle CMS. 2 difference instances are pointing to same Elasticsearch.

index rebuild work Unable to index metadata only. This may indicate the collection is damaged. Indexing aborted.

systemdatabase/6 06.29 11:21:56.328 index rebuild work !csMonitorActiveDbConnections,0
systemdatabase/6 06.29 11:21:56.328 index rebuild work Connection with id of 'index rebuild work.3' is removed from active connections with key of '18238'.
systemdatabase/6 06.29 11:21:56.328 index rebuild work release pool connection
(internal)/3 06.29 11:21:56.328 index rebuild work !csIndexerAbortedMsg intradoc.common.ServiceException: !csIndexerMetaOnlyFailed
(internal)/3 06.29 11:21:56.328 index rebuild work at intradoc.indexer.IndexerBulkLoader.handleIndexerResults(IndexerBulkLoader.java:601)
(internal)/3 06.29 11:21:56.328 index rebuild work at intradoc.indexer.IndexerBulkLoader.createBulkLoad(IndexerBulkLoader.java:373)