When unzipping a file in OS X rather than unzipping the files it creates a new file with extensions likefilename.zip.cpgz.
This is a wonderful quirk of zips and compressions. This can be caused by a corrupted file from the download site or an incomplete download, or simply an unrecognized type of compression.
- Download a different zip program, www.kekaosx.com. Install and try from step 1 again.
- If that still doesn’t work then try the terminal solution.