I'm working on a model of the space shuttle and built an articulated arm to be animated in a seperate file and imported it into the main scene. I parented it to the shuttle and animated it. Then I rendered a quicktime animation. I then closed the scene after saving it. When I re-opened the scene I got this message: "An object description is missing in the file. Do you wish to continue? (a cube will replace the missing object)" Sure enough, a part of the arm had become a cube. This fortunately, is not a big problem because I still have the original files and can set up the simple animation with no problem but I'm a little worried that it will happen again. I am on a Windows machine if that's any help.

Imagine waking up and having your arm replaced by a cube! I think this is an incident (a corruption in the file), I have never had it happen in my long Ray Dream / Carrara history. But I did have my share of files that no longer could be openened, which happened after a save gone wrong (across a network for instance). I got myself accustomed to saving multiple versions (stages) of things I am working on, mostly because of files getting weird... Good luck!

The only time I've had that happen is if I've created a shape using a plug-in and then open the file using a version of Carrara that doesn't have the plug installed. Were all objects created within Carrara or was one linked/imported? Hoof is right, it may be your lucky day and a one time corruption to the file happened. I'd create a fresh scene, drop in the arm and do a quick animation, close and reopen the file. If it happens again, I'd be in touch with Eovia PDQ.