4.2 -> 4.3 Mecanim Issues (Copy From Other Avatar)

So, in 4.2, I had a full exported mesh, texture, rig, and idle animation (named, let's say, Jim), and a host of other animations named Jim@Run, Jim@Jump, Jim@Crouch, and so on. The other animations did not contain mesh data, only the rig and the motion data.

Upon moving to 4.3, none of the individual animations seem to play or do anything. The new option, "Copy from Other Avatar", *seems* to make perfect sense (I always thought the "@" method was sketchy), but even after referencing Jim's avatar, the characters never move out of the idle state.

I'm not really sure what to do here; I'm out of ideas. This method *did* work perfectly in 4.2. Any tips, Unity bros?

Edit: After a few hours, I've learned that the behavior of "Empty" states in other animation layers now overrides lower layers, despite it being, you know, empty. Which was causing issues. Still gotta mess with stuff.