I had an issue like this a while back. It turned out the camera was getting freaked out. The figure was still there, but the camera was pointed who knows where. Change to a different camera if this happens, and see if you can locate the figure. My suggestion is to try the Face, and the Posing cams, unless you work with the posing cam, in which case sub in the Main cam. If you see the figure, you will need to fix the position of the camera you were on. Hope this helps!