Problem with polypaint in Zbrush



I’m new to Zbrush and trying to export my mesh with the texture that i’ve been working on. I have no trouble exporting the Obj file, but when it comes to exporting a texture/uv map… oh boy. I understand there are a few ways of exporting texture/UV map

  1. I’ve tried the UV Master Unwrap - Zbrush crashes. No idea why.

2… When i create “texture from polypaint” and turn the texture on, i seem to get these black polygons on my model.

heres a picture with the texture turned on:

As you can see, there are black polygons on the model.

I hope you can help me. I just want to export a clean UV map/texture map for my model, so i can import it into cinema 4d