@Vishesh  Sorry, but there is not enough information to give a definitive cause for your issue.  There is typically full stack traces to go with these types of logged exceptions which can tell us more, but even then it may not be enough information still.   As i mentioned before there are numerous improvements between Apache NIFi 1.23 and the last Apache NIFi 1.x release version 1.28.  I'd strongly encourage you to upgrade to see if your issue persists.   You may be hitting this bug  NIFI-12232  which was addressed in versions 1.26+.  Please help our community grow. If you found any of the suggestions/solutions provided helped you with solving your issue or answering your question, please take a moment to login and click "Accept as Solution" on one or more of them that helped. Thank you, Matt ... View more