I had this issue with my previous article as well.
I have resubmitted the zip files to the editors, so they should be available shortly.
I use WinZip, and I believe I have enabled some setting, somewhere, that makes it incompatible with normal zip algorithms.
I compressed the most recent files with the default Windows folder compression method. Hopefully this resolves the issue for this article, and I will try to track down which setting I have changed in Winzip to cause this issue.
One more thing, when you are able to go to the Browse Code tab at the top and view the files online, that appears to be the point when all of the readers that were having issues unzipping the files went away for my previous article.
Thanks for the compliements, and also thanks for you patience.