Point is on the axis of the smaller part and is on the face. A planar constraint is applied to the face and to the face containing the curve. The when a general connection with the point on Line constraint is applied, the problem occurs.
Added a snapshots of the screen. Point PNT0 is on the smaller part. The curve is on the larger Part say Ring. This happens repeatedly. Happened again now. Though the constraint specifies Point_on_line, I am able to select a curve, and vamooosh, I am out of Pro/E.