I don't have a Mac but there shouldn't be any permission issues, are the other games RPG maker games as well?
I'm sorry I can't help you much, I'd try asking the community forums.
Ok ok, that's not a bug, Bel warns you that there's a certain angle that is correct. Even if the image is "correct" it has to be in the right angle. Just a hint, head on the upper left and butt on the upper right. Also on the second puzzle there are already correct pieces meaning you don't have to touch some of them.