I received an error on B3 'no rate on file for this tariff treatment'. What does it mean?

I received an error on B3 'no rate on file for this tariff treatment'. What does it mean?

As per TCCU - user is using MUST (Mexico-USA), can use the FF Tariff treatment 2 3 7 8 9 10 11 13 14 21 22 23 24 25 26 27 8 29 UP TO 34. All these are free except tariff treatment 3 that has the rate of 35.00000. They are unable to provide exact code  because this depends to the Importer.