ok i just updated the drivers of the video card, now it let me snap the thumbnail and the rig is built for half a second and then it disappear and if i restart the rig creator the same error pops afterwards.
here’s the new error:
Error: ImportError: file C:/Program Files/Epic Games/4.12/Engine/Extras/Maya_AnimationRiggingTools/MayaTools/General/Scripts\ART_autoRigger.py line 9: No module named Modules.ART_UpperLegIKTwist #