Posted by Precise Simulation on
URL: http://forum.featool.com/Error-when-combining-objects-subtracting-object-from-flow-block-tp1633p1634.html

Thank you for reporting, that clearly looks like an issue with the geometry engine somehow. While waiting for model access.

As a temporary workaround I guess would be to first perform the subtraction with the small block, and then add the surrounding region (potentially with a hollowed out larger block). The drawback would be some extra internal subdomains and boundaries, but I don't think it should affect anything too much (and could potentially be useful to assign smaller mesh size closer to the submerged object).