Collision Models When Exporting Not Working - Help Needed Please

[Leg2ion]

Hi All,

After a steer if possible.

I have created an airfield - so dispersal and runway etc. I have added in both collision shell and collision lines and these are now 'solid' in that I can land on them. Not sure which does what so added both modifiers - but it works.

I then created and added 2 small hangars, as separate standalone models and cut/pasted them into the overall scene. I did the same (collision shell/line) and these are now solid - in that if I taxi into them I hit a solid object. When I created them (in Blender) I solidified and applied the modifier to the model.

I have now created 2 further hangars, added exactly the same collision shell/lines - yet can easily fly through them? The hangars have a solidify modifier (to make the walls solid - exactly as per my initial buildings - but it wasn't applied) - but if I apply it (thinking that to be the problem) - I then get errors during export (which it doesn't).

Not sure what I am doing wrong at this point - and is driving me crazy - having tried all different combinations...