>>368611450
Fix Model should only be used for stuff like MMD's, that's what it is made for. It takes a variety of input models such as MMD or XPS, and automatically applies a process to the armature that renames, reparents, moves or deletes a bunch of bones. This is so that a non-Unity compatible model basically becomes Unity-compatible almost immediately.
The catch here is that the models must be in a predictable predefined format (like MMD).
Booth models are ALREADY Unity-compatible, they don't have to be "fixed". They also aren't in a common format. If anything, doing "Fix Model" on booths will just have a chance of messing stuff up.
The nebbia model for instance will move around a whole bunch of spine bones in weird ways when you hit "fix model".