It's happened to me a couple of times. I end up having to convert to the "test avatar" and add the skin, shape, etc. If you have your skin/shape saved, you have a little less work to do. If you don't, you'll have to edit your avatar to your liking, and "save as". Once done, add all your little details.
I don't know what viewer you are using, but go ahead and look over all the tabs/dropdowns and see if you are able to locate your "test avatar".
If someone has a better solution, I hope they post it!
Good luck!