Problem: When attempting to install from 20.04 LTS ISO writted to a USB or DVD, no matter what combination, it always fails during the installation Copy process with dreaded 'SQUASHFS' errors. All online guides say the install media is broken, but multiple installs from multiple USB sticks or even a SuperDrive DVD all fail. Other guides refer to ACPI or DMA being the problem
Attempted: Tried various kernal paramters such as acpi=off and noapci (or something similar) and ide_dma mode off (something similar), but nothing works.
Workaround: Use the very manual mini.iso install, which installs by downloading all packagaes over the internet. It is very intensive, but it worked https://www.onetransistor.eu/2015/12/install-ubuntu-minimal-cd-uefi-enabled.html