"Morhing target mesh must be a single"

While attempting to import my workshop player models, I I received this compile error. What does it mean exactly?

The models in question were originally MMD (.pmx) files that I imported into Blender using a few tools. I exported them to .dae files. Thank you in advance.

Are you using our skeleton from https://www.towerunite.com/sdk/creating-characters?

That error means that you have some morph targets that need to be removed or exported.

If you make any progress on getting MMD models to work, please let me know.