Unzipping nvOC_v0018.zip (hash verified) on MacOSX using default Unarchiver or unzip resulted in corrupted file (I noticed this issue has been reported by several users). Because I don't have PC where to extract it, I found that Keka (http://www.kekaosx.com/en/) works perfectly. Keka is free unarchiver for Mac based on p7zip (7-zip port) and it extracted file without issues. Maybe it can be added to instructions for mac to avoid frustration for mac users.