converted assembly has invisible holes
I converted an " electronics print" assembly into a single part by exporting as IGS and importing again. For some reason random holes are now filled when viewed from the top side of the print, while they are hollow when looking at the bottom surface of the print. I cant select the filled surface on the holes and I cant remove them by cutting the holes in solid as well as trying a surface cut. Exporting to STP and importing does not make a difference.
Any ideas how to fix this?


