Yesterday I bought the book in the shop to unlock and upgrade all my heros. It seems a bug that all the three cards appear in one deck (because that deck is initially empty) and I play ladder with them.
Today I found that I only have one hero left in the deck while the other two were unlocked. Purchasing books in the shop won’t work. I tried to buy the Royal Wild Chest but if I was about to unlock a new hero, the game says “Login Failed! Invalid checksum in home state.” I wonder what happened because I can only unlock one hero now.