I downloaded the amd64 ISO image from UK Mirror and went through the installation without any trouble using the most basic/common selections.
System boots up normally, no trouble, gets IP address, setup reporting.
I then get asked "Do you with to enable a graphical environment? (yes or no)". I type in yes and press enter. The next thing on the screen is "mport: Package midnightbsd-desktop not found in the index.". After that it says to reboot t0 enable graphical login, which is probably not correct since the installation failed.