If you call the Emit method on a ParticleEmitter before waiting a frame or two after parenting it to a descendant of workspace, it does nothing.
Seeing that a lot of times the use case for a ParticleEmitter requires it to be created and instantly used, it’s a bit hacky and redundant having to throw a spawn and a wait there every time.
My suggestion is that Emit internally yields (not the thread that called it) until it’s ready similiar to the Play method of AnimationTrack which internally yields until the animation is loaded.