If you did the following:
This would indicate that one or more files in the Zip file has been:
None of these are supported by WinZip.
If you are certain that the Zip file does not contain any of these encrypted files, it may be that it is damaged or that it was created incorrectly. Otherwise, you may need to download and install the latest version of PKZIP to extract the contents of the file.
If you have any questions about this information, please email Technical Support.