When this bug started, MacCready started hovering along the ground (on his back). Then he would appear up in the air. Then he wouldn't move or take any commands. Everyplace we fast-travel to he just stands there. Won't move, won't shoot, nothing. At Med-Tec for his quest, he won't move so I can't get the key for the computer so at a dead end. Now going to drop him and move on because this is ridiculous and cannot be fixed until game patch, if Bethesda deems it worthy to fix. The pc guys fixed it by forcing him to move by entering a line code.

Shoot him, it resets the animation.