This article was originally written in 2014 when OS X Mavericks was new. Depending on the version of Liquid Rhythm or Liquid Music being installed, and depending on the operating system being installed on, this article may still be of relevance, though possibly with different system UI than those in the screenshots included below.
Liquid Music 1.8.0 + Liquid Rhythm 1.8.0 are notarized by Apple and should not display this warning, and are compatible from macOS 10.12 Sierra and up. You are more likely to encounter this issue with older versions of Liquid Music and particularly with older versions of Liquid Rhythm, especially on newer machines.
There is a new security feature within Mavericks that scans the apps and installers that you have download from the internet. You may get the above message when you try to install the Liquid Rhythm Clips Max Patch or Plugin.
Here is a step by step process of how to get around this issue.
Go to your System Preferences and click on Security & Privacy
Click on the lock to make changes and enter your password
Click on the lock again to make the changes and try the installation process again.
Please note that another possible way is to right click on the installer and click “Open…” and it will warn and allow you to open the installer.