The diff was perfect. It showed the problem was two input ports with the same name but different IDs, which I was able to reproduce. Your stack trace and flow diff helped us uncover a bug in our update flow logic -- thanks!
I verified it still affects the latest version of NiFi and I opened a Jira issue  that captures this. Feel free to sign up to ASF Jira to "watch" that issue if you want to see when this gets patched. In the meantime, you can avoid this by avoiding deleting/adding input ports with the same name (during a single version change) within a versioned process group. It's a pretty rare case that should not come up often, so I don't think this should impact your workflow for moving flows from dev to higher envs in general. If you do run into other failures in your workflow, please let us know.
On January 10, 2019 at 15:45:43, Russ Weiher ([EMAIL PROTECTED]) wrote: