Installing Java on macOS
MinimServer and MinimWatch are written in Java. To run them, you need to have the Java runtime installed on your Mac.
If your Mac is running macOS 10.13 (High Sierra) or any later version of macOS, you should install the current version of the Java JDK (JDK 21). If you have Java 8 installed, this might tell you that Java is up to date but this information is incorrect. Java 8 is a very old version of Java and has bugs that can cause MinimServer or MinimWatch to fail to start or to crash.
JDK 21 is recommended because this is the latest version of Java that has long-term support. MinimServer and MinimWatch have been tested extensively with this version. See the page Installing the JDK on macOS for details of how to install this version.
If your Mac is running macOS 10.12 (Sierra) or any earlier version of macOS, you need to install Java 8 because later versions of Java are not compatible with your version of macOS. See the page Installing Java 8 on macOS for details of how to do this.