"Prohibited Sign" when trying to boot Mojave install drive

[Ravenlost]

Hey there,

Hoping to clear this out..

First, my specs:

Motherboard: Gigabyte Z370 AORUS Gaming 5 (bios F11 - my understanding is that F12+ requires additional patches in clover, so haven't touched that!)
CPU: Intel Core i7-8086K
RAM Memory: G.Skill RipJaws 5 Series Noir 32 Go (2x 16 Go) DDR4 3200 MHz CL16
Hard drive: Samsung SSD 860 EVO 1To
Video: Sapphire RX580 Radeon Nitro+ 8GB (kept iGPU enabled to enable Intel QuickSync).
Thunderbolt 3: Gigabyte Titan-Ridge

So I already have OSX 10.13.6 running on my machine. All is good, but I wish to do a clean install of Mojave.

I've got a copy of the 6GB+ Mojave install file in my /Applications/ folder.

I am able to create a USB install drive using UniBeast 9.2.0 - Mojave. This goes flawlessly. I choose UEFI boot mode, and I didn't inject any ATI or NVidia drivers. USB gets created no problem.

HOWERVER, when I try to boot from my USB stick, I only get to a prohibited sign like so, and nothing else !

Has anyone else gotten this issue ? I can't possibly believe it's something with my BIOS, since all is working right now in HS 10.13.6... But if it helps, here's my configs from BIOS... :

Save & Exit → Load Optimized Defaults
M.I.T. → Advanced Memory Settings → Extreme Memory Profile(X.M.P.) : Profile1
BIOS → Fast Boot : Disabled
BIOS → LAN PXE Boot Option ROM : Disabled
BIOS → Storage Boot Option Control : UEFI
BIOS → CSM Support : Disabled * CSM Support first needs to be enabled to see the LAN PXE and Storage BIOS options above
BIOS → Secure Boot : Disabled * You’ll find this at the very bottom of the page. Keep scrolling…
Peripherals → Trusted Computing → Security Device Support : Disable
Peripherals → Network Stack Configuration → Network Stack : Disabled
Peripherals → USB Configuration → Legacy USB Support : Auto/Enabled
Peripherals → USB Configuration → XHCI Hand-off : Enabled (Extremely important)
Peripherals → Initial Display Output : PCIe 1 Slot
Chipset → Integrated Graphics : Enabled
Chipset → DVMT Pre-Allocated : 128M
Chipset → Vt-d : Disabled
Chipset → Wake on LAN Enable : Disabled
Chipset → IOAPIC 24-119 Entries : Enabled

ALSO, do note that I did plug in my USB drive into a USB 2.0 port and NOT a usb3 port..

Many thanks in advance for any tips in solving this! Cheers.
Pat

 

[P1LGRIM]

Has anyone else gotten this issue ?

Many people have, we see it almost every day - Search for prohibitory symbol and still waiting for root device.