High-bandwidth Digital Content Protection (HDCP) is a system which encrypts the signal passing through the HDMI cable connecting your TV set and YouView box. HDCP requires authentication from both devices and if this fails, the signal fails producing this error message.
Reboot your equipment
Switch off your Plusnet router, BT Openreach modem and set top box either via the wall socket or the power switch on the back of each unit (where applicable).
Then, after 30 seconds:
- Switch the BT Openreach modem back on and wait until the DSL light turns green
- Switch on your Plusnet router and wait for the Internet light to turn green
- Finally switch your set top box on, and check if you're still having problems
Check the cables
Make sure the HDMI cable is connected securely at both ends. The quickest way to do this is remove and reconnect the cable.
If your TV has more than one HDMI port, try using that one instead (remember to change the input source on your TV to the corresponding socket).
If you're able to, switch the HDMI cable out for another one and try again.