Bug report: I got to a late-middlegame position and then the bot crashed because it tried to castle illegally (after its queenside rook had already moved):

``` Uncaught Error: Invalid move: {"from":"e8","to":"c8"} at Chess.move (chess.js:2530:23) at cm-chessboard/:75:23 ```

There didn't seem to be a way to recover besides refreshing.