From your post it sounds like the error you are getting is on the control, correct?
If so, then you probably need to direct this question to the Vectric Team.
From my experience over the years this sort of problem is rare on controls these days. It used to happen much more frequently in the bad old days. Generally speaking it is usually a rounding problem within the control software. If you think about it a bit it becomes apparent that numbers have to be rounded off because very few tangencies calculate out to precisely 4 decimal places. So they have to be rounded. I would guess after about 15 years and lord knows how many postprocessors Vectric probably has the rounding correct.
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