I had an older computer that I was repurposing an older workstation. Thought I would make a media server. I threw in a CD of Ubuntu 14.04 and I got this error....
mount: mounting /dev/sda on /media failed: Invalid argument umount: can't umount /media: Invalid argument
Thinking about this a little, I realized that in the bios the legacy floppy was still enabled. Going into the bios and disabling the legacy floppy drive corrected the problem.
I understand that we can never account for everything, but it having the installer bypassing a floppy drive should be something that should be taken into account.