Bios Mods -The Best BIOS Update and Modification Source

Hi,

i want to get PCIe SSD Support on my ESPRIMO P710 (Mainboard D3161-A12).
I followed this guide, but i cannot flash the bios, it says 1d - Error: Failed to load image into memory.

Is it possible to make the M2 SSD work via PCIe?

Edit:
I followed this tutorial to unlock the bios, but i can't make it work. It still says 
Error 28: Protected Range Registers are currently set by BIOS, preventing flash access.
Please contact the target system BIOS vendor for an option to disable Protected Range Registers.

Edit 2:
I found AFUDOS v3.06.01 and tried to install with /GAN but it stops at Erasing All Block ............ 0%

Did i miss some informations, or can't it be solved?