straw hat matt

That's what I followed. Has no mention of my software update error.

2018 MBP

using balenaEtcher. I tried another one but it didn't work at all.

No option appears in Disk Utility for ext4 (or 3). sorry this is reaching the limit of my knowledge

my ssd or usb drive?

My error: when booting off the drive in the boot menu, it says I need a software update to use the 'disk' My steps: I used disk utility to create a partition on my SSD, (MS-DOS, FAT32), 110gb I used disk utility to erase my flash drive and reformat it as above (ms-dos, fat32). I downloaded ubuntu as .iso, and used etcher to flash it onto my USB. I reboot, enter boot menu. Even though I only have one flash plugged in, two identical usb drives pop in the boot menu. They are titled the same and both produce the same error. Other steps I have attempted: I gave clearance for my computer to boot off an external boot drive. I removed all security features from my computer's drive and any boot drive. My laptop is fully updated. After clicking the boot drive in the boot menu, it reads : "A software update is required to use this startup disk" If I click update, it goes through a 'downloading update' phase for a few minutes, then automatically boots back into Catalina on the other partition. Please let me know what other details I can offer Thanks!