Hi there @X11
Are you on MacOS Mojave or Catalina ?
During the install process just bypass the MacOS warning to complete the installation.
You'll find more info about this in the last topic How to open an app that hasn’t been notarized or is from an unidentified developer from this Apple Support page https://support.apple.com/en-us/HT202491
If you managed to install KICK 2 already and see an update notification from the plugin UI, then your KICK 2 version isn't up to date. Latest version of KICK 2 is v1.1.4 , you can download the latest installer from your Sonic Academy user account, be sure to be logged in and check this link.
FYI --> @bryan_spence @phil_johnston several users reporting this issue, Plugins installers might need a refresh to be compliant with new Apple apps requirements. Might be one point to look at for future releases.