I downloaded one or several ZIP file(s) from your product and it appears to be corrupted.
This can be a somewhat common problem especially when you download large sized ZIP files. If you did not download the ZIP file to its fullest file size, the ZIP file will reveal an error that it is corrupted when you try to open the contents, thus revealing nothing.
Try downloading the same zip file using Download Accelerator Plus (it's a free download tool you can find from Google). That should solve the problem.