Class JavaLaunchHelper is implemented in two places
Mac 上的老bug，jdk版本 java version "1.8.0_144", 在java启动时使用了-javaagent参数时会触发。 此问题通过升级jdk版本即可。 You can find all the details here: IDEA-170117 "objc: Class JavaLaunchHelper is implemented in both ..." warning in Run consoles It's the old bug in Java on Mac that got triggered by the Java Agent being used by the IDE when starting the app. This message is harmless and is safe to ignore. Oracle developer's comment: The message is benign, there is no negative impact from this problem since both copies of that class are identical (compiled from the exact same source). It is purely a cosmetic issue. The