ATP Error with out ATP enabling

Hi Team,
We are not using ATP functionality in our project (never enable any ATO at the instance level or org or item level), but the time of order entry we are getting error message like "Scheduling failed: ATP processing Error - We are not using ATP. Arrival Date :<Date>"

Please any one aware off, how can i find where the ATP is calling at the time of order booking.

Thanks,
Dhasa