Also if you see that message just press the game buttons, whatever they are set to, and you will skip over that message.
Just mentioning it in case you didnt know.
But yeah, the sub-circuit board is a peice of hardware in a real game cart used to save games that some emulators dont emulate properly, but you can just use save states instead.
That message comes up for me as well. I dont understand how i am meant to skip it? I pressed every button that does something on the game and it just stays there. I went to play pokemon fire red and it comes up after i press start to play the game after skipping the introduction movie thingy.
One time it went out of this message and went back to that 'this game is loading, it may have a black screen for a while' message but it doesnt load anything.