Houdini to UE4 HDA cook error

[inversionstudio]

Hi guys, I'm following a houdini (sidefx) tutorial and am getting a strange error in UE4 houdini engine when trying to run a simple test.
I have two hda's, one for terrain and one with scattered points. I'm trying to get UE4 to replace those points with UE4 meshes using attr randomize and setting the mesh paths from UE4, very similar to this tutorial:

https://www.youtube.com/watch?v=2zWLF_q5284&list=PL65uAWxiUNxEUnjlDagf7uo2eXOjzxBS7&index=5&ab_channel=Houdini [www.youtube.com]

Here's my two subnet hda's, one for terrain and one for scattered points:

 

This is the terrain subnet:

 

This is the scattered points subnet:

 

And this is the attr randomize node that I am using to replace the points with UE4 meshes once imported into UE:

 

When I import this into UE4, I get this error:

Cook Results:
Geo (ID: 2709): /obj/hda_scatter_1_2/hda_scatter1
No geometry generated!

Cook State:
Ready with Cook Errors

===================================
Node Errors, Warnings, and Messages
===================================

/obj/hda_scatter_1_2/hda_scatter1/maskbyfeature1:
Error: Not enough sources specified.

/obj/hda_scatter_1_2/hda_scatter1/maskbyfeature1/attribblur1/cl_compute_edgeweights1:
Warning: Zero sized attribute, doing nothing.

/obj/hda_scatter_1_2/hda_scatter1/maskbyfeature1/attribblur1/cl_smooth_generic3:
Warning: Zero sized attribute, doing nothing.

/obj/hda_scatter_1_2/hda_scatter1/maskbyfeature1/attribblur2/cl_compute_edgeweights1:
Warning: Zero sized attribute, doing nothing.

/obj/hda_scatter_1_2/hda_scatter1/maskbyfeature1/attribblur2/cl_smooth_generic3:
Warning: Zero sized attribute, doing nothing.

/obj/hda_scatter_1_2/hda_scatter1/points_trees:
Error: Not enough sources specified.

Any help would be appreciated, many thanks!