Modded BIOS file fails to flash, "Selected file is not a proper BIOS!"

[MrAnonymous7122]

Apologies if this is a silly issue, but I would like some help.

I am trying to use ReBAR. I followed what the guide said exactly.

1. Get latest version of BIOS for your motherboard(I have Asus H110M-R BIOS Version 4210)
2. Open BIOS File with UEFITool and add the ReBarDxe.ffs to the BIOS file.
3. Open the ReBarDxe BIOS file with UEFIPatch and use the patches.txt
4. Enable Above 4G Decoding and disable CSM
5. Flash BIOS and ReBAR should be working

However when I try to flash it to the motherboard using EZ Flash 3, it gives this error.
I'm not sure if it's worth noting that this motherboard needs a .cap file for BIOS.
I remember there being something about "Aptio signature may be invalid" when using UEFITool and UEFIPatch.
I have also made an issue on the ReBar repo but I was wondering if the problem is to do with UEFITool.
Thank you for spending your time to read and any help is appreciated.

[NikolajSchlej]

Use a dedicated SPI programming hardware (CH341A-based programmers are cheap as dirt and fairly reliable), Asus likely finally implemented some verification routines for their EZ Flash software on the TPU/EC.

[MrAnonymous7122]

Do you know if it's possible to use a Raspberry Pi as a programmer thing? I have one on hand but if not, I'll look at getting the CH341A thing.

[NikolajSchlej]

It definitely is: https://winraid.level1techs.com/t/guide-recover-from-failed-bios-flash-using-raspberry-pi/30264

[MrAnonymous7122]

Thanks for your help, the winraid guide was a bit out of date but more or less helpful and I have rebar working successfully.