cant set variable using efi error: 0x800...01a

[AlexCazacov]

I've been trying to turn on the VTd on my HP Prodesk 600 G1, it has an i7-4400 which is VTd capable, the computer originally came with an i3_4300 I think which wasn't; capable of VTd the option is hidden in bios so I figured this grub mod will help me out, but every time I try to change the setting on for VTd (0x238) it gives me the same error every single time I've even tried the other commands such as setup_var_cv but there's no luck.
Any suggestions would be very appreciated

[ZibeSun]

I also encountered this problem

[gabevf]

same

[ChisBread]

I'm having the same problem