For this particular problem on the Mac it is a bug in Wineskin which is only encountered when running on the recently released High Sierra operating system. The OS reports GPU information in a slightly different way which then exposes a string parsing bug in Wineskin.

This one can be solved by changing a setting in MoI as described here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=8592.4

- Michael