There is no real clue that comes to my own mind. If you still doubt that it is working, consider setting the interval to something as insane as 1000 feet. See if that works. If so, I think you can be fairly confident that setting it to 20 ft or 100 ft will eventually get you a model, however long that might take.
Without knowing more about your model, I can't really give you much further help or advice.
Except along with this, I would consider disabling (not deleting) each point control and parametric constraint, set the drop frequency to something useful, then turn on each point control to see if the model looks right each time.
Without knowing more about your model, I can't really give you much further help or advice.
Except along with this, I would consider disabling (not deleting) each point control and parametric constraint, set the drop frequency to something useful, then turn on each point control to see if the model looks right each time.