Ran into this issue the other day, I'm not entirely sure why it affects one leg but not the other.
They're rigged the same way and the biggest issue is "undo" won't fix the problem!
Legs are set up with path and IK constraints (like stretchyman)
The problem occurs when you lock images and move the IK around, the mesh becomes.. 1 line entirely?
undo does not undo this effect
video of the issue:
https://gfycat.com/GiantFixedAzurevase
