If you have both an eclipse and a nightfall on the field, strange bugs happen. First put on a nightfall, then play creatures. When you play eclipse, anything already on gets +2/+1, but new creatures you add after the eclipse is played only get +1/+1.
If you are disconnected from the internet, the reconnecting can cause bugs. If you try to reconnect while drawing a card, the card draw animation will play, but no new cards will be added to your hand.
If you have an empathy on the field with a vampire, the empathy's healing won't stack with the vampire's healing.
