Flashing black screen with error message.

My main TV (with DirecTV DVR) suddenly stopped working. I'm getting a flashing black screen with the error message as follows:

"Your TV does not support this program's content protection.  Replacing the TV's HDMI cable with component cables will allow you to view the program."

It seems that all channels are affected on this one TV but the other secondary TV works normally.  When I view using a streaming service (using the very same HDMI I've had all along) everything works without issue.  Can anybody tell me what is happening and what is the "component cable" the system wants?

Thanks.