With the release of macOS 10.15 Catalina, Apple introduced security changes that are not compatible with the official OSMC installer. As a result, users on macOS Catalina and Big Sur wanting to prepare a bootable OSMC image, cannot use the official OSMC installer and need to follow these steps instead.
While these steps describe preparing a bootable OSMC image on an SD card for Raspberry Pi, they may work for preparing bootable SD cards and USB flash drives for other OSMC supported devices as well.
- Go to the Download page and download the desired OSMC Disk Image (bottom of the page).
- Download any SD card flashing app (tested with Etcher).
- Launch the SD card flashing app and insert the SD card into your Mac.
- In the flashing app, select the downloaded OSMC Disk image file as well as the desired target SD card. Flash the SD card.
- Once flashed remove the SD card from your Mac.
- With your Raspberry Pi powered off, insert the flashed SD card and power on the Raspberry Pi.
- That’s it - you will now see the OSMC installation on your screen!