Hey! I think I got it. I started again from scratch. I changed Chip ID to C2 in the original template, put in my header. And then I think I found the faulty value. The MYSTERY BYTE. Sky Army Knife told me it is 01 for Pokemon Y. Since sky army knife lets you select the mystery byte: 0x00 then followed by 0x02 .. I typed in 01 myself. Cold that have been the mistake all along??