On Mac OS
- Open System Preferences > Security & Privacy.
- On the General tab, if Blackmagic is being blocked, you will be prompted to allow it. Select Allow.
- Close and relaunch the Blackmagic Desktop Setup and select the correct Input (SDI or HDMI).
- Open the Thunderbolt Control Center and go to to the Approve Thunderbolt Devices area.
- Confirm the Device Is Listed, and change the setting from Do Not Connect to Always Connect, then click OK.