I am running macOS Sierra on a Macbook 2010. I followed the instructions at https://tutorials.ubuntu.com/tutorial/tutorial-create-a-usb-stick-on-macos#0.
When I try to boot from the flash drive I get the following error message:
[ 9.911831] Couldn't get size: 0x000000000000000e
[ 9.911867] MODSIGN: Couldn't get UEFI db list
[ 9.929086] Couldn't get size: 0x000000000000000e
[ 9.946311] Couldn't get size: 0x000000000000000e
[ 10.447589] nouveau 0000:04:00.0:bus:MMIO write of 0000807e FAULT at 100c1c
Does anyone have any suggestions?