This is a known issue which affects all Unity versions. The issue: Building Android project with the IL2CPP backend fails after the OSX Catalina update. The reason: OSX Catalina does not want to run unsigned binary files as they are considered unsafe. Unity uses NDK versions up to r19 and all of them are not signed. This causes Android builds to fail. The workaround: This issue is only reproducible on the OSX Catalina, so not upgrading to this OSX version or using Windows is a possible workaround. Alternatively if you have already upgraded to Catalina, each NDK tool necessary for Android building can be allowed to run in the OSX security and privacy settings. See this post or this thread on how to do that. Just note that there are multiple tools invoked while building Android and all of them must be allowed to run, so you will have to start build process multiple times for this.