SpaceCadet23

tldr; Figured it out. It looks like the installer does NOT like usb3.0. I started out trying a CD which allowed me to boot but still had issues after loading into the install with kernel and set failures. Next, I tried using Ubuntu and dd'ed the image to my flash drive and then booted via the USB 2.0 port and was able to select UEFI. (Side note here: this probably works with bios as well but I wanted to use UEFI) The version I am installing is FreeNAS 11.2-U3. My PC is a random Aliexpress special Chinese Micro PC that doesn't have vendor information anywhere that I can find. USB 3.0 worked under the old grub install method but the changes made to the custom boot do not play nicely with the USB 3.0. May post this on the FreeNAS forums and see if anything can be done about this.

It looks like the grub bootloader was removed in favor of their own bootloader I think this has something to do with the non-booting when flashing via USB. I was able to efi boot when I copied it to a CD but still had a kernel failure and was not able to boot.

Hey @sandhill, I had this same issue today. It Turns out that RUFUS was writing the flash drive with gpt even though it says mbr (For those who say it doesn't matter because rufus uses DD mode, I'm not sure of this after the issues I had ). Use win32diskimager instead. You may have to use linux to update the partition table possibly before you will see the flashdrive in windows (Disk manager showed the flashdrive but would not allow me to edit it). I had tried 5 flash drives of different types so had to update the partition table on all of them again. Also, I was able to boot in UEFI mode after this as well. UPDATE: tried this again with a different version and still ran into issues so YMMV. UPDATE UPDATE: so the last version that will work is 11.1-u7. From what I can find, the newer versions go to the USB as a GPT partition which for some reason will not UEFI boot on the machine that I have.