If I use a model that a client shared with me (fbx), I have no problems and it works correctly. I am uploading the config.json, environment_map.hdr and the model.fbx files.
When I try to do the same with a model of a T-shirt created in Clo, the web preview (Fancy Product Designer) doesn't work. In the Chrome console I get the following error:
FPD3DPreview.js: 120 Uncaught TypeError: Cannot set property 'map' of undefined
at FPD3DPreview.swapTexture (FPD3DPreview.js: 120)
at Image.image.onload (FPD3DPreview.js: 135)

I am creating the models with Clo3d and I assign the name "custom" to the material and the part to be customized as requested. Could you tell me how to export the models so that it works? If you like, I can send you the complete projects so that you can open it and compare the differences between the one that works and the one that doesn't. I understand that it is a problem when exporting the garment, since with another FBX file it works.

Many thanks in advance!