I am suffering the same problem described here. I am setting the JoltSpecification property using expression language, but something it's going wrong. My NiFi version is: Powered by Apache NiFi - Version 1.5.0.3.1.1.0-35 02/25/2018 20:13:30 UTC Tagged nifi-1.5.0-RC1 I create a POC with an UpdateAttribute that is creating the attribute 'transformRules' with the value: [{"operation":"shift","spec":{"*":{"PartNr":"[&1].PartNumber","TcdMakeID":"[&1].Description","TcdCountryCode":"[&1].PartPrice"}}}] Then I have a JoltTransformJSON processor that uses this attribute as Jolt Specification, and the components looks like this: ideas about how can I solve this issue? Thanks in advance. ... View more