[HUMAN IK] Assigning new source deeply deforms mesh.

[fabio_gi]

As shown in screenshots, assigning new source to Character 2 deform its mash. What would be the cause? What would be a solution? 
(P.S. Hip alert doesn't show up in t-pose, but I cannot get rid of the "arm parallel to x axis" alert, but somehow I don't think it's because of it, moreover it show-up only defining hands. )

 

[hamsterHamster]

In the leftmost image I see no roll joints for the upper hips.. can't it be the cause for the knee distortion? As for the hands - it is indistinguishable in the screenshot.. can be that the metacarpals are missing.