what is a .cpgz file and how do i open it?

thanks for the answer. Ive also found that one can use Onyx to fix these files which can then be unarchived with whichever tool you wish. Sign into Onyx app. Go to files/checksum and pick your algorithm and point it towards the file to be fixed. Wish you could batch process these files though. no way that I know of to do that.