Pivot Painter 2, can't get the x-vector map to export properly.

Hello! I managed to get pivot painter 2 working after fiddling about with it a bunch previously, but couldn’t put my finger on a concrete, workflow that led to it finally working consistently.
And now I am having the exact same issue. I cannot get it to create the X-vector map properly. It just becomes a pink, flat texture instead, leading to only some vertices moving at the same rate.

My current process is:
Create the mesh.
Set the pivot point to where I want it to behave as a base for the motion.
Reset and collapse X-Form, just to be safe.
Bring in the script.
Paint the vertices.
And finally, process the object hierarchy to create the maps.

However, this leads to the beforementioned issue.
I’ve tried doing things in all sorts of orders without success so far. Sometimes things move slightly, sometimes not at all, sometimes only one part of the mesh moves.
Any ideas of what I am doing wrong?