Importing a hollow sphere

Firstly, I’m a noob with UE4 and blender. I’m trying to import a sphere from blender that your character can go into. My previous test mesh imported well, but when my character was inside the object only the entryway was visible, the rest was invisible. I went back and made some adjustments to smooth out the mesh and now it crashes whenever I try to import.

  1. How do I make the inside of my imported hollow mesh visible?

  2. What would cause this to start crashing, as I only added a comparably few vertices?

Thank you

In unreal make the texture 2-sided in the texture editor. Also for some reason I find that unreal crashes after editing as well since 4.9 update. Try deleting the asset and importing fresh

Apparently I just wasn’t being patient enough. Though the program said it wasn’t responding, it was still working.
I just had to wait about 1min per MB (or 11 min.). And 2-sided texture was the piece of information I needed, so thank you for that.

Anytime =) please mark this as correct answer so in the future others can find it when searching for answers like this. Cheers!