Commonality calculator gives engine type not valid value erro

Modern Times, Dobbo Airlines Brazil.

When toying with the idea of getting Pilatus PC-12 aircraft for ultra low density routes I tried to use the commonality calculator but when I selected either engine type under the add to new fleet type tab it gave a “Engine type is not a valid value” error.

I had tried with both engines and various quantities of aircraft but was not able to run the calculator in any scenario for this aircraft type