Health bars and tab screen don't work then I crashed [client] [crash]

In one of my ranked games today I noticed when I pressed tab all the champions where piled on top of each other and trying to move them off each other sent them back to the top of the tab screen. I also couldn't see champion health bars including mine, teammates. and enemies. I could still see minions and I wasn't paying attention until minions spawned so I decided I'll restart my game at a good time. Then when I reached level 3 my game crashed and I couldn't alt tab or even task manager so I had to sign out on my computer and go back in. It worked fine afterwards, but the time I lost was immense. This bug already happened twice to me the first time I restarted before reaching level 3 as it wasn't a ranked game. I think the cause is when I alt tab during loading screen, but I've done that before and the game ran fine.