Glad it worked out for you '>
As far as I know, the presence of the cap holes modifier does not cause crashes; however, I always convert my meshes back to editable meshes before I apply an aurora trimesh modifier so that there are no other modifiers present on the visible geometry.
Also, if you used the cap holes modifier and the model seems to be fine in your 3d modeling software but parts of your geometry are invisible in the game; then you should take a look at how to ''flip normals'' (not saying this is the case now; I had this on a few occasions though).