I created a bootable linux USB following Ubuntu's tutorial. When I startup the machine holding Option an EFI Boot drive shows up. When I select it, it goes to Apple Logo Loading > Then Light Grey Screen > Apple Logo Loading Again > Then the messages below show up:

enter image description here

With internet, I can update whatever this is, it takes 4 minutes, then the machine reboots to normal Macintosh HD. When I boot back again it keeps asking for an update. I updated 4 times and it stills shows up.

Without internet, the message below shows up: enter image description here

When I click "Startup Disk" the EFI boot does not show up and all I can select is my Macintosh HD.

enter image description here (this image is from a forum, my Macbook is up-to-date, MacOS Catalina 10.15.4)

Googling up I found this could happen because of T2 chip securities, I disabled all of it's securities in recovery mode. The problem persists. What may be causing this issue? How can I fix it?


1 Answer 1


I am having this exact same issue following the exact same Ubuntu Tutorial. Have tried a multitude of variations with the security settings...but nothing helps and after it's downloaded something (approx 70%-ish?) the screen goes black, comes back on with Apple logo and boots into my regular Mac HD.

My supposition is the process breaks the OS and we have to follow a different path to run this software.

EDIT: To add, and an FYI, following the same Ubuntu tutorial from above, but now for a bootable DVD instead, gives the same 'error' loop. It appears (to me at least) that any kind of external media, whether that be USB flash drives or DVDs/CDs, currently aren't supported by the Boot manager under MacOS (Catalina: version 10.15.6) despite lowering/altering the T2 chip's security settings.

EDIT 2: as Topic starter mentioned below, 2019 Macs do not support alternative OS other than Windows for now. Thanks for all your insights and let's hope someday Ubuntu will also be supported.

  • 3
    I think we keep this, it confirms the issue and there’s no quick fix. Knowing a process with lots of steps repeatable breaks helps people know what to do like try another plan for Ubuntu. Ideally we rescue things with a more clever answer, but let’s keep this up even if that happens.
    – bmike
    Commented Aug 14, 2020 at 11:47
  • I later found out that the MacBooks 2019 do not accept OSs but Windows 10. So installing any Linux on it breaks the system.
    – RA828
    Commented Aug 15, 2020 at 14:40

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