Had the problem too. Installing
Code:
linuxcnc-2.8.4-buster.iso from a 32 microSD card in a USB reader. Created iso on the card in linux using command line dd. Could launch LinuxCNC from USB boot, but wouldn't install. Failed to read CD error.
Created a new ISO on an 8GB microSD card using Rufus and dd mode on a windows machine. Then it worked fine.
