Train classifier scope error

Hi all. New to UIPath here. Apologies for the repost (as I may have listed my previous post in wrong section). I have some issues while trying to create an automated invoice detector where the field would be automatically accepted once it reaches a certain confidence level.

  1. It detects the value of classifier as null but I have actually ticked the field within “configure classifier”

  2. I provided exactly one field under “Human Validated Data” and left out “Human Validated Classification Data” in which the system wants me to only provide a field (which I did)

How can I fix this issue?

Some other information:
I followed the exact step of UiPath Academy