Are there 15 unique qubit pairs, or are there 30? E.g. is Up+Down the same pair as Down+Up ? To me the word 'pair' implies that the order doesn't matter, however my Quantum Decoders are only partially working, and the only explanation I have is that the order the qubit pairs are loaded is a factor.
(If the order is important, my feedback would be that the Quantum Decoder description be updated to clarify this).