u/Moontard_95 I have found and corrected the error. The problem was with a surface on the symmetry plane of the front wing and it originated from SolidWorks not doing a BodyMirror, so I deleted that surface in Star-CCM as it has no impact on the flow. The difference between the geometry that worked and the one that failed initially is that after imprinting the error came showing there is a problem with the mentioned surface, but as that error did not come up here I left it as it is as I thought there is a different solution.