I wanted to modify a first person animation, but, the 'Extend any existing model' option completely disappeared, and I can no longer import Arm Models and then import draw.smd animation because the mesh completely messes up. With the 'Extend any existing model' option the mesh looked fine, but now its completely distorted and messed up.

Is this a bug or intended feature? If its a bug, is there a work-around for now?