Animation stopped working on 3D Emitter

I assume I pressed some key combination and disabled animation of a 3D Emitter. The 3D object used by the Emitter works and its animation is enabled, ie. Play animes it fine.

But I have no idea why the Emitter using it does not show on the screen. It stopped all of a sudden while editing. Emitters are so tricky to tweak, and I would hate to have to redo what I did so far.

Any idea why my 3D Emitter stopped working?

5.9