Maya 2020: Quick Rig + Attach Hands

The Quick Rig Tool that was introduced in Maya 2017 allows users to create a HumanIK rig for a human character with a single click. Unfortunately, the Quick Rig Tool doesn't create any bones for the fingers.
This video shows how you can manually (and quickly) add a hand skeleton (or any other skeleton parts) to your character during the Quick Rig process.


PROBLEM: after saving the character and loading it again the Control Rig seems to be broken, the handles will not move anymore.


Here' how to fix it:
When I copy the left hand over to the right side (after deleting the original right hand) the DEFINITION of the HIK character is broken.
What you need to do now is:
in the HIK panel in the "Definition" tab turn off the "Lock" icon - this will delete the Control Rig - the regular skeleton is now visible
select the joint of the right hand
in the HIK panel hold the right mouse button over the GREY bone icon of the right hand and choose "Assign Seleced Bone" (the icon turns green or orange)
turn the "Lock" icon back on
in the HIK Panel pulldown menu "Source" choose "Control Rig" - a new Control Rig appears, should be working now
I hope this works for you.