.zip file you provided is not exactly a file, which you can get from a download page after login.
WordPress plugin installation .zip file should not contain any other directories except plugin parent directory – user-role-editor-pro in our case. Your file contains _MACOSX folder. May be it’s a reason of security warning?
Did you try to upload to a site the exactly that .zip file, which you got from a role-editor.com download page?
_MACOSX folder contains hidden files with the same names as at the original package, but with the content made probably by antivirus software with this string inside: “com.apple.quarantine”. That is all PHP files was placed to a quarantine for some reason.