Model-Based Definition > Geometric Dimensioning and Tolerancing Advisor > Advisor Message Help > DRF Messages > Orientation of Secondary Datum Not Allowed
  
Orientation of Secondary Datum Not Allowed
The orientation of a secondary datum that is derived from targets must be perpendicular to the primary reference of the datum reference frame. This problem causes the DRF to be considered a failed object, as indicated by a separate 'There are failed objects in the model' message.
You should either redefine the datum reference frame or redefine the datum from targets.