LoadFromCacheOrDownload and PlayerPref.SetFloat (WebGL)

I'm using `PlayerPrefs.GetFloat` and `PlayerPrefs.SetFloat` to save the player's personal volume preferences. This works great, until I create a coroutine that contains a basic, nearly copied from the manual `LoadFromCacheOrDownload`. Loading the game to test, after the bundle loads (automatic and immediately before switching scenes) and upon initially trying to save (using `PlayerPrefs.SetFloat("randomString",0.5f`), I get the error "Invoking error handler due to TypeError: invalid arguments". It seems to **read** the settings just fine. The sliders are set perfectly when I go into the options. It just throws the error on trying to save. Is this a bug with WebGL? I haven't been able to find anything else about this problem.