Firmware Updated 1.25

Hey guys!

I'm currently running 1.24 on my XDJ-XZ and want to update my firmware to 1.25. I have a 256GB USB that's currently formatted ExFAT and when I try and load the latest 1.25 firmware file on my XZ nothing happens. Is my USB formatted incorrectly? In Disk Utility I only have the options of ExFAT or MS-DOS(FAT) as formats... 

Any info would be much appreciated!