Build shows skinning errors on other PCs.

hi all

so I build this mini game. It runs totally fine on
my machine (win10, i7, gtx970) and
my laptop (win8, i5, GeForce 940MX).

Today I let the guys at my company play it, and there are strange errors on the weightmap. On I have never seen this before. I tried it on three different machines - same errors.

A (Win10, i7, gtx 970)
B (Win10, i7, gtx 1080)
C (Win10, i5, gtx 1060)

Besides the graphics it runs as expected.
Any idea what that could be?

thanks

parts of the body get distorted as if the weight maps were messed up. all over the model, not just the face.