Yellow Trinket not found

While in game, and I have seen this happen with my friend as well, we were exited out of League of Legends about 20-30 minutes apart from when ithappened, and both of us recieved the error message that while in game (summoners rift normal) that League could no longer find the Yellow Trinket and we were both asked to Uninstall the game and then re-install, as of last night I have not seen it happen again but it was very confusing.