Nifi unable to start Cannot set Concurrent Tasks to 0 for component JoltTransformJSON

[#1]

Hello All,

My nifi instance crashed due to some infra issue and when I restarted it, it gave the following error -

Caused by: java.lang.IllegalArgumentException: Cannot set Concurrent Tasks to 0 for component JoltTransformJSON[id=9d443567-014b-1eab-654a-69ea31a12f53] because Scheduling Strategy is not Event Driven
  at org.apache.nifi.controller.StandardProcessorNode.setMaxConcurrentTasks(StandardProcessorNode.java:661)

I had to manually edit the flow.xml and flow.json and set concurrentTasks to 1 to bring the docker instance up.

The question is, since NiFi does not allow setting concurrentTasks=0 with CRON_DRIVEN from the UI, how did so many processors end up with that setting.

No one manually interefered with the flow.xml.gz or flow.json.gz
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Did anyone else ran into the same issue ?
Any pointers will be helpful

Thank You

[#2]

I just had the same issue. Had to manually modify the `flow.json.gz` like you did.

Strange that the UI let me set it to 0 in the first place.