I've had this issue with every SDK version 3.7.3 and beyond.
Anything involving the new constraints doesn't work for me at all.
In a new project, I would constrain a cube to the left hand of my avatar. Upon pressing play mode, I get 10 of this error in the image. When exiting play mode, my console gets infinitely spammed with this error. When re-entering play mode, the cube is no longer following the left hand of my avatar.