(MAC) Loading screen turns black, not sure if still loads or not

After everyone locks in their champion, the loading screen pops up right? It goes full black for me and I don't know what to do. I tried restarting but it takes me bad to the blackness. The only way to escape the loading screen for me is unplug my computer. But when I reconnect to game, it just goes back to the black screen

Sorry for bad english