Hi, I am trying to create couchbase document_id (PutCouchbaseKey processor) as json key "stud_id" using expression-language but i am getting below error. due to uncaught Exception:org.apache.nifi.attribute.expressac_noguage.exception.AttributeExpressionLanguageException:Subject is empty. Keys:- {stud_id,first_name,last_name} My Teamplate:- ExecuteHQL->SplitAvro->AvroToJson->PutCouch nifi1.PNG -- Sent from: http://apache-nifi-developer-list.39713.n7.nabble.com/