you have your model probably very far away from the origin, point 0,0,0 in archicad and then you are having troubles with triangulation in art*lantis.
try to replace your model near the point 0,0,0 (the origin) (a origem) and you'll have your problem solved.
models away from the origin can give problems, it's very easy to make that mistake in archiCAD, because you can be thousands of km away from that point, and then art*lantis will be asking for correction.
regards
cumprimentos