hi there, i've made a blender model(2.69) of a container with a cut out for the entrance(no bbolean operator, just a loop cut), when i import it to GG the cut out is not there anymore.
i've tried many times to re calculate normals, flip them etc. etc still nothing. could someone help me please?

from what i can see is that you have not Uv textured around the door,
as your uv texture is texturing right over the enterance.

Edit i re textured it and its not that,
so i loaded model into blender and door way shows its there. also the other side wall has gone and just a door is there.
so it looks like a model problem.
i will have a look at the container x model in another program and see how i get on.

i have noticed loads of little dots around the model. and stretched verticies from inside wall off where the door is but outside is fine.
i would say is redo that wall with a hole new wall and see how that works.