If you are downloading from the Solutions Download Center, download the self-extracting archive (.exe) and follow these steps:

Licensing

Once the Setup program has installed all of the files, it will prompt for the licensing information.
Note that global setting of license servers (by explicitly defining the MSC_LICENSE_FILE environment variable for your computer) supersedes the license setting done by MSC Apex Generative Design during installation.
The MSC Licensing Helium software can be downloaded in the Solutions Download Center to solve licensing issues. For more information regarding licensing and how to use MSC Licensing Helium, please see the MSC Licensing 11.13 User’s Guide.

Allowing Installation with Security Software

In order to install MSC Apex Generative Design, the application and its lock server must be allowed to execute by any security software on the system. MSC Apex Generative Design is whitelisted with Symantec, but users with other security software must add exceptions that allow the MSC Apex Generative Design lock server to run. If these exceptions are not made, the security software will prevent MSC Apex Generative Design from installing.
If a security error occurs during Apex GD installation, users should manually add Apex GD installation folder to their security software's exception list and then start the lock server using lsconfig.bat. lsconfig.bat is located at:
"<INSTALLATION_FOLDER>\leaf\Services\EOM\WIN8664\bin\lsconfig.bat".