I had kinda a same issue yesterday. I bought a killer pack (17.000 astral gems) in Shadow Lords yesterday. It gave me a Killer Ram card and some some other cards and astral energy. After I got my items from the killer pack the screen turned black and only the surrounding background (of when the game shows You the cards You got from teh pack You bought) was displayed. The game did not respond to anything anymore. I had to close the game and restart it again. Thankfully the game registered all the items I got from the killer pack. I play the game on Xbox One.