Comment 5 for bug 1462676

No... you are not listening. The reason it failed is because it tried to install to /dev/sda instead of /dev/sda1. Aparently in an EFI system that does not work. If my EFI partition was corrupt, I would not have been able to boot into Windows either. The moment I realized what it was doing, I pointed it to /dev/sda1 specifically (which it should have known to do as it was running on an EFI system) then it worked. I don't know how many other ways to explain this.

That is why I wrote that perhaps, the writers of the installer script should take into account an EFI system and maybe have it look for the EFI system partition instead of always defaulting to the MBR instead. That was just a friendly suggestion.