Nothingness:
Look at White moves 58 and 59
You'll see the 5 moves from i1 to h1
Then from h1 to i1
It violates the rule that a piece cannot move back to the square it had vacated on the previous move..

Dark Prince:
I just looked again at the game to see how many pieces the player making the illegal move had on the board and noticed that there was another illegal move prior to the one I indicated.
On moves 54 and 55, the 5 was moved from h1-g1 then g1-h1.
In this case, the player making the illegal move had 3 movable pieces and 2 in the other case.

Nothingness: