HDCP

- Try resetting the HDMI connection by disconnecting the cable on both ends, then re-connect.

- Avoid using HDMI adapters, splitters, etc. that may not support HDCP. Avoid converting video to analog signals.

- Avoid using a monitor/TV/projector/screen that doesn’t support HDCP.

Your display must support HDCP, and you can only use an HDCP-capable path to connect to the display. HDMI is typical. As mentioned above, no splitter, no analog adapters, it’s got to be wired digital and HDCP-capable all the way to the display.