Is this a .pkfx file? if that's the case, indeed, maya can't read those.
The usual workflow for PopcornFX is:
Maya / photoshop > PopcornFX > Game engine
you'd use maya to create 3D meshes that will then be used by popcorn as mesh particles or emission/projection surfaces, then save your particle effect as a .pkfx, and import this .pkfx in the final game engine to play it back (UnrealEngine4, Unity, or a custom engine)
Why did you need to get the effect back into maya? perhaps there's another way to do what you had in mind?