im trying to build a reactor i saw online when looking for a good sized and efficient reactor.

http://forum.feed-the-beast.com/threads/big-reactors-a-spreadsheet-mechanics-summary-and-reactor-example.45647/

It says "White = Annything, I preffer Glass, but can also be air." meaning, the blocks in the corners can be "anything". is this outdated? or is alfheim glass one of the few exceptions because it creates light?
It honestly looks too cool its worth looking into i think.

my problem is when i try to form the reactor it says "alfheimglass invalid interior block" and shows the coords of the alfheim glass.