From February 3, 2020, Apple has tightened the "notarization" requirements for applications for macOS Catalina. As a result, when installing Live2D Cubism Editor 4.0.04-beta1 or later in the environment of macOS 10.15 Catalina or later, the warning popup of the following words is displayed.
Apple can't open this software because "Live2D_Cubism_Setup_4.0.04-beta1_jp.pkg" is not malicious software.
To start the installer in this state, you need to perform the following steps.
1. In the Mac Finder, search for the downloaded installer "Live2D_Cubism_Setup_4.0.04-beta1_jp.pkg".
2. Right-click (Control+Left-click) and select Open from the menu.
3. A dialog will open. Click “Open”. Enter your administrator name and password when prompted.
For details, please also refer to Apple's user guide.
Live2D is currently working on "notarization" and will soon distribute a notarized version of the installer.