The card "Anticognition" has sometimes Incorrect rules interactions.
Most of the time it plays well, canceling the oponent creature spell, when it does work correctly it plays by itself. (no targeting is required)
But sometimes it asks you to target the spell you want to counter, and when you do so, it doesnt counter anything.
This is not related with the oponent having 8+ cards in graveyard or not, nor the oponent being able to pay the 2 mana cost.
The card in both situations sometimes plays well and sometimes doesnt.