Many BluRay, DVD’s and video downloads include HDCP (High-bandwidth Digital Content Protection) - in theory to help reduce digital pirating from HD disks or files when the source has a digital output such as HDMI, DVI or DisplayPort. Such copy protected sources will only be compatible with more expensive HD distribution systems – including HDBaseT - where the manufacturers effectively pay an annual levy towards the copyright.
If you wish to play such copyright protected material then you will need to ensure that you have an HDCP compatible AV/distribution system. NB. These will still not allow for recording from HDCP copyrighted sources.