Ahh, I see 
When I export a part into primitives (something you can do in MLCAD) so all the subparts are broken down to to there quads and triangles, you couldn't see the BFC in LDview. I don't know if that was any clearer, but I know what the problem was now
I have attached the .lpc to this post. It still crashes when I export it, but I have managed to export it by copy and pasting all the vertices into a new .lpc without a template (as you can see with the attached .dat file).
When I export a part into primitives (something you can do in MLCAD) so all the subparts are broken down to to there quads and triangles, you couldn't see the BFC in LDview. I don't know if that was any clearer, but I know what the problem was now
I have attached the .lpc to this post. It still crashes when I export it, but I have managed to export it by copy and pasting all the vertices into a new .lpc without a template (as you can see with the attached .dat file).