This version you posted doesn't work properly but the one you posted on Cocrea works, I'm not sure why it doesn't work here but potentially you posted a version where it thinks the player already crafted all elements. 

I think the unbugged version posted on Cocrea is actually really cool my only critique is that sometimes depending on the order that elements are mixed they become different elements(example earth and fire) I'm not sure if that's intended or not but it's more of a preference on my end.