If you are installing Livestream Producer on Mac and encounter a installation failure or a "System Extension Blocked" error message, this is due to Producer's audio driver likely being blocked by Mac OS High Sierra's security features.
To resolve this error, close the installer, open System Preferences, and navigate to Security & Privacy.
Under the General tab, you will see a message indicating the extension that was blocked. Click Allow to prevent Mac OS from blocking any future installations from Livestream.
You must then restart your computer for this change to take effect.
Reinstall Livestream Producer using the package that you previously downloaded. If you need to download this software again, you can do so here.