Gameplay Bug NO HUD

I was simply playing a normal draft pick However when the game started, there was no HUD at all. I tried to see the scoreboard, nothing. I couldn't see the minimap or my champion's hud to show which of my skills to level. The only thing that would appear is the chat box and the options interface. I don't know how to reproduce this bug nor do I want to. I just want to bring it to your attention.