I generally have pretty good luck with stuff or can eventually figure things out but occasionally, I get something that just won't work so I understand your frustration. I don't know Jack about Macs so I can't offer any help in that regard. From the APple threads, it sounds like this is something that is hit or miss and probably down to the specifics of the exact OS version, installed applications, patches etc. Those problems are extremely difficult to figure out. Without knowing what application the creator used, it's impossible to say if that is a factor. Obviously though the file works normally on multiple PCs, with multiple applications and on some Macs with some applications.

Rather than beating you head against the wall, I would again suggest that you either unzip it on another computer if you have access to one - preferably a Windows machine - or, contact the creator and ask her to send you the files unzipped - or give permission for someone here to send them to you. If there is no contact information listed at sharecg, I can send you the email listed in the readme.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken