Converting nParticles
 

Hi hi! I'm new to the forum and kinda new to Maya, and I have this issue that's been irking me for the past two days.

I've been modeling this scene and I want to use nParticles to create a piled up snow effect on some surfaces (like a tree, a fence etc.).
I know how to go about doing it from watching a bunch of tutorials - duplicate the faces I want to particles to emit from, 0 gravity, random size, and emit.
I have the amount I want to be emitted and it's looking good as a bunch of particles, but I want to convert them to polygons so that the snow can be in my scene as an object on the tree/fence/blah blah blah.
However, when I select the particles (or the emitter, I've tried that too) from my outliner and go Modify>Convert>nParticles to Polygons it gives me an error saying "No nParticle nodes were selected" and doesn't do anything. So I went into my node editor and selected the particle node in there and tried to convert that, but I still get the same error. I've replicated it in numerous clean projects and all have the same result.

Am I doing something wrong? Can somebody help? It's driving me absolutely CRAZY.
If you need some images of my scene/outliner/whatever I'm happy to upload them, too.