Old board, new board? Model? Witch tool/method used to make the dump?
These are things that need to be told upon such request.
Mod files usually cannot be flashed using regular procedures, so its not surprise at all, the secure flash errors…
Heres a guide for some guidance, not entirely applied to all hardware around or recent but can give you an insight of it:
[Guide] How to flash a modded AMI UEFI BIOS - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum (level1techs.com)