[Unable to boot Unraid on R420]

I just tried plopkexec.... didn't work aswell

[Unable to boot Unraid on R420]

Hi, I am unable to boot from the unraid USB-stick. my problem is similar to this post:

but I'm not even able to MBR boot. Please halp.

R420 - latest firmwares

H310 Perc Mini

16gb ddr3 ecc

 

unraid stick: Intenso Rainbow 16gb usb 2.0

 

I tried the UEFI option in the USB creator: same result

I ran the make bootable batch file as administrator and pressed Y when I was asked if UEFI boot should be allowed.

didn't help