Help, my UE4 keeps crashing!

Okay so i made a castle, nothing to be all crazy about but it took me like 20 hours of grudgingly building it with how analytical and stuff that i am…
plus it was my first map ever…

I tried to export it as a .fbx then load it into the new editor 4.15.0…

First it had to load (145/145) it would always make it to (144/145) crash and not load it…
so i spent a long while trying to figure it out on my own, and ended up downloading Maya, imported it as .fbx, it loaded with ZERO textures, everything one colour…
i exported as .fbx and imported that into the UE4 4.15.0 project and it worked, but the entire thing is one colour now…

anyone able to help? pics are below…

Picture in spoiler, it’s kinda big, i combined 4 of them so you could get an understanding.

[spoiler]