When I open a CC3 Avatar in CC4, it loads find. However, when I try to Export FBX (either for Blender or Unity3D), I get a generic "FBX Export Failed" message. No hint at what the issue is. I tried converting to a GameBase but had the same problem. I did try exporting a CC4 avatar and that did seem to work. So the issue is not with all content.

"We often compare ourselves to the U.S. and often they come out the best, but they only have the right to bear arms while we have the right to bare breasts"
Bowser and Blue, Busting The Breast