Bone constraints not working on first bone in chain I have an IK chain controlling a mesh. I want to attach this IK chain to something. I have tried putting Child Of, Copy Loc, and Copy Transform bone constraints on the start of the chain. None of them do anything. Is there some rule against using constraints on the first bone in a chain? I notice that it works if I constrain the bone in Edit mode with a regular constraint instead of a bone constraint in pose mode, but this causes some strange issues.

Anybody know how I can go about attaching my bone chain? Specifically, I need to have it following a specific vertex (vertex group) on a mesh that is being simmed, so it doesn't work to constrain the entire armature object, or to constrain to the object. Is there an option better than constraining the bone in edit mode to an empty, and then having that empty be constrained to a vertex?

EDIT: Example file (see comments)
The issue was with the bone at the start of the chain being set as Connected. This is because the bone chain was made using the Skin modifier on a vertex chain. Normally if you add a bone and then extrude it to make a chain, the first bone is not Connected. Apparently the armatures made by Skin are. The Connected checkbox is greyed out, but still can be unchecked. Since the bone has no Parent, the Connected status was locking it in place.