Whats is wrong with my Formula?

Hi, i need help, i don't know why, i am trying to do a Subtotal for my excel, however, i keep getting Error when i do the sumif portion.
I uses Index, by right, should work, but i dont know y, it keep getting error.

Morever, my z only has 6 value, however, when i do the sumif, the list by right should be 6 also, but i get a lot more.