Cassiopeia's miasma is invisible in over 50% of the games I have played against her. I have played cass and it still shows on her screen when she is played. There is still a cast animation but the only way to know where it went is when everything around it gets poisoned.
I had this same bug in my game, only with janna and fizz ultimates, I was using the lowest setting for character quality and switching it up to low made the bug dissappear.
So I recon there is rendering problems for ground aoe markers, which don't seem to render with some specific options. This needs testing.
Very much gamebreaking for those who experience it.
Repro steps: start the game with (certain drivers? or options?) notice that something is missing.
