Evee Emission Particles Volume Bug

Im a complete blender beginner.
I got a question:

My emission particles do not look right.
When I try to change the material from surface to volume, blender crashes at rendering.

The blue pic is mine and the yellow from youtube. How can I make my particles look like his?! It seems like its not a real light particle, it doesnt really cast shadow? The Colorramp doenst work as well.

I guess nobody knows what I mean, sorry :blush: