This issue should have been fixed after the latest public version. Your GPU doesn't support a very specific graphic pass used in the skin shader. This has been fixed with an option in the settings menu around v0.4, and has been fully fixed for everyone (without settings need) around v0.5, so all you can do to resolve this specific problem is to wait for the next public version haha (v0.5.6, which is targeted to be for the end of summer if all goes according to plans). Thanks a lot for your interest and see you soon! ♥