When you use Safari browser on an Apple computer and download WPML and its add-on plugins’ .zip files, Safari will automatically unzip them. This happens due to Safari’s default behavior.

To solve this issue you can either disable this option in Safari or try using a different browser to download WPML and its add-on plugins.

To disable this option, open Safari->Preferences and in the General tab, uncheck the Open “safe” files after downloading option at the bottom.

Option for automatic opening of "safe" files in Safari browser
Option for automatic opening of “safe” files in Safari browser