error 9

[ffffff]

I tried to play MarioClassic's World 9-castle,and 1-up falls to lava,then I got this error.

[bossedit8]

To prevent that stuff to happen, make sure there is no way that a Mushroom (any kind) falls into Lava. You can also make them "speed=0" to specific NPC's so they are not moving.

[FutureNyanCat]

This error happens when a mushroom falls into lava while there are other stuff happening at the same time. This also applies to 1up mushrooms, too. To prevent this from happening, both mushrooms have to be set to speed=0 or the game will crash. I remember also encountering this error too when I was looking at Chad's sample Batafire boss battle and I spammed mushrooms while the boss battle was going on, causing the game to crash.