Hi @mmoura , The error that you encountered in nifi 1.16 is appearing because of some changes introduced in nifi starting from 1.16 version.

Starting from nifi 1.16 , NIFI start writing on flow.xml.gz as well as JSON format ( prior to 1.16 this JSON was not there ) flow.json.gz , see the link https://www.mail-archive.com/users@nifi.apache.org/msg15332.html

When 1.16 nifi start it creates both the file, writes onto it and then encrypt it using props key from nifi.properties , when your code run encrypt-config.sh tool it only changes the flow.xml.gz with new props key and JSON flow file still encrypted with old props key, While next time nifi going to start it try to read props key from nifi.properties , which is the new ( changed props key ) and it successfully able to decrypt the flow.xml.gz but it can not able to decrypt flow.json.gz because JSON file is still encrypted with old props key which is overwritten by new props key on nifi.properties

Solution : from 1.16 onwards "./bin/nifi.sh set-sensitive-properties-key NewSensitivePropertiesKey" tool improved to cover both xml as well as json version of flow file while changing the props key, see JIRA ticket https://issues.apache.org/jira/browse/NIFI-9711 , So while changing the props key you can try using nifi.sh in place of encrypt-config.sh

Regards

Vikas