Bizarre! I thought that problem was fixed but I guess not.
The zip file itself is not actually corrupt, it’s a couple of the files within it. You can extract all of the files apart from two which are missing their file extensions. I had to manually extract all the PHP and CSS files, then I had to open the images folder and extract all of the files apart from those two without extensions.
Sorry about the bug. I’m actually rewriting the entire system from the ground up right now (just stopped to check in here on the forum) and that system won’t have the problem at all (it won’t use zip files).