When I was going to ReInstall a fresh copy of Catalina MacOS on my Macbook pro 2019, unfortunately I deleted all partitions instead of erasing them. As my internet connection is so unstable as much as I repeated installing the OS from the net, it was failing with different errors usually related to the network errors or corrupted raw data.

I created a bootable media flash drive by these steps .

Now when I want to boot the device from the USB drive,

it says "Security settings do not allow this Mac to use an external startup disk".

I waned to allow my Mac booting from external media (as this link ) but It shows me the error: "Authentication Needed - You will need to authenticate as an Administrator to change the boot security settings."

And when I click on Enter macOS Password I see this error : "Recovery is trying to change system settings. No administrator was found."

I had never set a password for my mac bios and also I've removed my Macbook from my apple account too.

I've searched a lot and watched lots of youtube videos but didn't succeed anything yet. How can I fix my issue to allow me boot from the flash drive?

5 Sorted by: Reset to default

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