Invisible Mundo W

[GAMEPLAY] Mundo W (Burning Agony) is Invisible

Specifically Pool Part Mundo. Pressing W will play the sound effect, proc his E, drain your health, and do damage, but will not display the fire around him. Happened on Butcher's Bridge ARAM map then recreated it in a Custom game on Summoner's Rift. This happens both with and without items and regardless of level points put in to the skill.