This is the second time this has happened to me. Not being able to Castle queenside. I am a relatively novice player, but I cannot see why I am unable to make that move. Here is an example game.
You can't castle "through check." After 12...Qxd1 13.Rxd1, the rook on d1 is preventing you from castling.
White rook on d1 , is the reason. (King has to cross the d file)
3.8.2.2 Castling is prevented temporarily:
3) If the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one or more of the opponent's pieces, or
3.8.2.2 Castling is prevented temporarily:
3) If the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one or more of the opponent's pieces, or