Just for practice, I tried making a TAS for the first room of Kirby and the Amazing Mirror (JP), but when I tried to play it back from frames 0-8 nothing happens and the game doesn't run. From frames 9 (First frame of BIOS?) or 275 (ROM load I think?), it works perfectly. And when I try to record a movie from power-on, the video goes black for a while before erroring with a NullReferenceException.
Did I set up my project wrong or something? I can't figure this out...
Using BizHawk 2.3 if that helps.
edit: Tried making a movie from frame 275 and got the same error. Making an AVI works fine, though.
edit2: Tried making a movie from a couple other early points, same error. Here's the error text (because that's a thing):