Bug when replaying complicated FEN positions?

There's this 64 piece chess puzzle I played through in a game against myself (using the custom FEN position feature), and it seems like there's a bug when replaying the game: http://nb.lichess.org/3Q2hLR0t

Here's the ending position: http://nb.lichess.org/3Q2hLR0tS48q

what FEN string you input?

This one: "brkrqbqn/qnpNqqbr/bnNqRbrn/qNrrnRrb/BrqnbqRr/bqRNnprR/QQbNNrNn/bqrnRbKb w -"

It's a mate in 8 puzzle. Seems like it's pgn4web that won't display it.

You can have max 10 same pieces. If you have 11 or more, then the FEN is illegal, probably thats why it cant be replayed.