I had no problem to display the 3D view of your file on my computer.
Note that I fixed yesterday in the version 4.3 beta some more issues that could happen under Mac OS X in multiple screen environments. If this is your case, while waiting for the final release, please circumvent this issue this way if you can't use the beta version:
- Quit Sweet Home 3D
- Use your computer in one screen mode
- Open your file
- Display the 3D view (it should work)
- Save your file
- Turn on other screens again, and don't display the 3D view on other screens until the final release of version 4.3.