This has been happening to me since the last update. Game ends then black screen. Close app and reopen and I get pushed into Choose your hero screen with no options. If you tap some of the options quickly before you get shunted into the Choose hero screen you can some times get the "unable to connect" which I assume is where the error lies. I too would like to play more than 1 game in a row and hope it gets fixed soon. Frustrating to say the least.