Sony has released MacOS X Driver Loader to enable firmware update compatibility with MacOS 10.13 High Sierra. MacOS 10.13 users must run this driver loader BEFORE connecting your camera.
Please Note: MacOS 10.13 users must run “DriverLoader_1013” prior to ALL firmware updates.
1. Run MacOS X Driver Loader for 10.13 High Sierra
2. Once Driver Loader is finished Open the Firmware Update and follow all directions.
3. Connect the camera via USB when the firmware instructs you to – and NOT before.
Mac OS Security Settings must be set to:
System Preferences > Security & Privacy > Allow apps downloaded from: App Store and identified developers