Captivate 2017 intaller failure message, MacOS

Trying to install Captivate 2017 on Mac w 10.15.4 Catalina OS. Have a license. Downloaded the package from website, got message "Error: The installation cannot continue as the installer file may be damaged. Download the installer file again."

Downloaded twice now and getting the same message. Is there any way to have this package updated on the website? I already have a license for 2017 Captivate, and it is a work license. Can't upgrade right now.