A friend has been working on this and sent it along to me. Neither of us can get it to work.

He created this file in Swift 3D v4.5, but at one point, it seamed to be not displaying all the shapes on screen. So he saved it right away and tried to open again. However, When he goes to open it, swift just crashs.

I've had a look at it and the same thing happens. The file (the only copy) can't be opened. we have both tried a demo of V6 to see if it works in that, but it just closes the program automatically without even an error message.
Since it's too large to allow me to attach the file, I've temporary hosted it here: http://www.tesp.co.uk/MasterEmeraldShrine.t3d

I've made larger myself so I can't see the problem, but it just will not open.. It's a good days work and it'll be annoying to lose it. And it'll be a pain to remake from scratch, even more so if it'll crash again.