Thanks in advance for your assistance.

I am trying to edit version F4 of the BIOS for my motherboard to disable IOAPIC 24-119 Entries in the Chipset configuration of the Motherboard to fix issues with internal USB and SATA on OSX El Capitan Hackintosh. Disabling this setting has fixed the issues on other motherboards, however us Gigabyte owners are having problems modifying the BIOS.

I used AMIBCP64 5.01.0014 to adjust the value to Disabled, and saved the file.

I then attempted to flash it with QFlash from the BIOS and via USB bootable DOS with the Gigabyte supplied Efiflash DOS utility. Both methods say it is an Invalid BIOS file and will not flash.

I then tried adjusting the value back to original (in theory what should be an unmodified version F4 BIOS) and it would not flash via both methods again.

This is leading me to believe that the AMIBCP program is not editing the BIOS correctly. Possibly due to the new Z170 chipset?