The blood interface recipe is using minecraft:fire as it's center component, which is uncraftable through vanilla means. Co-incidentally, trying to render the fire block crashes the (wasliecore) book API.

@Tombenpotter Why haven't you removed that stupid old book, yet?

Hey I'm doing it soon! I modified the build.gradle to start yesterday, but I fell asleep on my keyboard.. I'll do it today :P

Fixed, and moved over to Guide-API