[HTML5] Crash with PickingCollider on 3D scene in Away3D

I am converting an Away3D project from AS3 to Haxe, and I have a problem with mouse picking: I have multiple meshes on stage, and I need to catch mouse event on them.
I am setting these properties for each mesh:

meshX.shaderPickingDetails = false;
meshX.pickingCollider = PickingColliderType.PB_FIRST_ENCOUNTERED;
meshX.mouseEnabled = true;

This worked in AS3, but on Haxe when I hover the mouse on a mesh the game crashes and the console spits out these lines

Uncaught TypeError: Cannot read property 'get_data' of null
    at away3d_core_pick_PBPickingCollider.setLocalRay (PBPickingCollider.hx:49)
    at away3d_entities_Mesh.collidesBefore (Mesh.hx:367)
    at away3d_core_pick_RaycastPicker.getPickingCollisionVO (RaycastPicker.hx:206)
    at away3d_core_pick_RaycastPicker.getViewCollision (RaycastPicker.hx:103)
    at away3d_core_managers_Mouse3DManager.updateCollider (Mouse3DManager.hx:81)

Any idea?
Latest libs, HTML5.

We do not support PixelBender in OpenFL currently, so you’ll need to try the HAXE_FIRST_ENCOUNTERED picker instead for now

Do you have experience with Away3D 3? I know a project that needs conversion from Away3D 3 to Away3D 4, but I’m not sure what the migration path looks like

Ah, sorry, you already told me about PB, I forgot about it: as soon as I can I will set HAXE_FIRST_ENCOUNTERED and give it a try.

I started an old project on Away3D 3, but 4 came out immediately after, so I had very few to change.
What is the project you’re talking about?