Hi Mate
I remember I had this problem when I was messing around with my TV settings, everytime I would open the screen this message will pop up and the screen would go blank.
I cant tell you exactly how to fix it, but I pressed the 'TV' button which gave me 4 or 5 option columns along the top of the screen and I went one by one setting it to another setting. Eventually came across the right setting and there was no message and I got my TV picture.
What I think this message is about is that its saying that it cannot find an active device on the input its set to, so you need to change it to an active input much like the AV1, AV2 stuff on your TV, but im not certain I'm not Japanese.
Hope it works out