I had to move some stuff around which resulted in having to unplug my Denon X2000 and input devices connected to it.
I did not disconnect any HDMI chords, literally, just unplugged power for maybe 10 minutes.
When I plugged back in - no input source recognized on my TV. The input sources to the AVR (DirectTV and PS4) pass through fine (I can hear the audio)...but seems like something going on with the HDMI from the Denon to the TV.
I can't even get to the Denon menu - because the TV does not recognize any video coming in. Did the powering off reset something I don't know about?
I'd suggest first verifying that all of the HDMI cables are still fully seated, especially the cable between the AVR and the TV. Push on both ends. The HDMI connector doesn't latch and can easily wiggle its way out slightly but look like it's still in all the way.
Another thing to try is to do a soft-reset of the TV while the other devices are all in standby mode. Unplug the TV from power for about 10 minutes. Then turn on the TV, followed by the AVR, and finally the Blu-ray player.