Skatchup Faces Gone?

Hello Unreal Users.

First of all i would like to Apologize for my bad english.

I have some problems with importing FBX files to Unreal, Some faces are gone after building lightning.
I readed this is because i used sketchup (Yes i know not the best “3D” Software but it is easy to use for me).
But is there a way to fix this? i searched for a while on google but cant find how.
A screenshot of the problem :

http://s11.postimg.org/5cqnk5bsx/Howisthisposible.png

Greetings, JaWillem