Hello:
I have a very similar problem. I worked with Sweet Home 3D (Version 2.2 Java Version 1.6.0_17) on my iMac (10.6.2) for hours and saved my file on a regularly. I put my Mac in standby to continue the next day. Which I did. But when I tried to save the file then, SH3D said it could not. So I closed the application and reopened it. I also reopened my file and now I see all these red boxes and the background picture is missing, too.
While working, I had created different versions of the file (01, 02, 03 etc.). Older versions of the model still work fine, so I do not think it is a problem of moved or missing objects, although not all objects that I used in the corrupted file are available in the older versions.
I did not understand, what OBJ and MTL files are, but I tried both tips above with terminal, but no success.
What should I try next?
Thanks,
Hal
