I am trying to change the mannequin for my character.
I can retarget the animations without problems.
Everything seems to be going well, until I duplicate the blueprint and replace the mannequin with my character.
The warnings are related to bones that are apparently fine.
if you click on the Control Rig name/text the node where that control rig is set will open. The issue you have is that you are using an leg/hand IK control rig for the original skeleton mesh. The one from where you’ve got the Animation Blueprint.
You need an Ik control rig for your skeleton. This rig is basically to have the foot Ik work correctly in game. This is why your feet look wrong.
select the Control Rig node and you will find the option to change the IK leg rig. Double click the node and you will see how a leg IK should look like
Hi there,
Just to confirm, does your custom character have ik bones? If not, you may need to add virtual bones and replace that names in the Foot IK control Rig
If you mind watching timelapse videos, I recorded this one with metahuman.
Thanks, this work for me. 
Glad it helped. Keep up the good work.
