I am placing an updated atx Gigabyte mobo in an atx case, and am having one hell of a time, fitting the io shield. I just cannot get the 4th corner. Yes, I’m fitting from the inside. It is definitely the correct shield, and and an atx board has been successfully used in this case previously. Any ideas? Would there be any real harm, running the system without the shield? I’m guessing the board’s internal grounding would suffice.