Openelec won't boot from USB on an Intel NUC 2820

[AppleII]

On an Intel NUC DN2820FYKH, Openelec won't boot. I created the USB from a MacBook Pro with El Capitan (tried with 2 different USBs) with the official guide but in UEFI, right after the boot of the NUC, the Intel logo splash screen appears on screen, with on the top left the following string:

press [tab] to edit options:
Boot

After a few seconds, comes another black screen with:
Error in mount_flash could not mount UUID and some numbers.

    IMG_1799.jpg[/attachment]

In legacy mode it says: Reboot and select proper boot device.

Please let me know what do you think is the error.

For the record: The NUC has an SSD with Kodibuntu installed in it. What I'm trying to do is to format and install OPENELEC (which I think is much faster).

[klojum]

Kodibuntu is a full (Lubuntu) Linux setup, OpenELEC is of course a simple plain vanilla Linux build with the bare essentials to run Kodi.

You could browse through this topic for the rest of the year: http://openelec.tv/forum/64-installation...dn2820fykh

It could also be that the boot sector of the flash drive is somehow corrupt. There is a tool that cleans usb sticks / sd cards quite well, but it is for Windows....
http://www.softpedia.com/get/System/Hard...Tool.shtml

[AppleII]

Managed to solve this problem by trying to make the bootable USB more carefully with the OS X Terminal. It was my fault, because I was flashing the image into the EFI part of the USB (disk3s1) and not in the whole USB (disk3).