Everything Disappeared [CLIENT]

Ok, so I was just playing a normal blind pick game with my friends in a 5 man, and everything was fine. That is, until about 10-12 minutes into the game. I was going to type something in to the team chat, but then when I began typing everything disappeared -- my entire HUD, my minimap, the bar at the top of the screen that shows the score and time, etc, the in-game chat. I couldn't access the shop or scoreboard using the hotkeys. I couldn't even press 'esc' to exit the game and reconnect. Also, using abilities didn't work; I was stuck running around the map, auto-attacking without being able to help my team with my abilities. Furthermore, some health bars got bugged and the green was missing; all I could see was a black bar, and my own health bar above my champion went missing.

This has only happened once, however, and I'm unsure whether it is a bug that's just affected me or if it has affected anyone else as well. Hopefully it isn't a recurring bug and that I can go into games without being worried about this issue ever popping up again.