If the monitor or screen that you are using does not support HDCP, then the user will not be able to use the XMP-6400 with HDMI-in for the live feed in. To use the HDMI in function, you will need to turn off the HDMI function in the configuration settings.
To accomplish this :
1. Go to Advanced Settings.
2. Click on System.
3. HDCP -> Disable
If you are using a sending card for a LED wall, the sending card may not necessarily support HDCP and you will need to disable HDCP as well.