hi @hackerway,

It seems that you have the same exact issue as posted here: https://community.cloudera.com/t5/Support-Questions/NiFi-ListSTFP-hostprovider-may-not-be-empty/m-p/...

I had the same issue and what @MattWho said in that post helped me solve my issue 🙂

Have a look to the solution and try to see if it will solve your issue.

In addition to the above link, you can also have a look on: https://stackoverflow.com/questions/59826510/a-hostprovider-may-not-be-empty-after-upgrading-to-nifi...