I crafted a couple new rare cards to add to my deck for historic. The cards appear in my collection but it would not let me save the deck and exit. When I exited the deck-building part of Arena it completely deleted my deck. I re-created it from memory and every time I try to find a game it says "network error". I tried restarting the client without success. If I used a different deck it DOES work so there is some issue with a new rare card in my collection not working.