Black mess?

Hey there!
I had the same problem with my meshes before and in my case it was due to me joining my top with the nude top, making too many overlapping verticies. Did you by any chance do this?

If you just played around with the mesh then it looks like it could be something to do with lack of vertex painting.

Here is a link to a tutorial of vertex painting if this is your problem:

sims4studio.com/thread/2479/vertex-paint-sims-4-mesh

(To sum up the tutorial above if you are still stuck after reading it, you need to make the parts of the mesh that do not touch the skin Green- the specific green that is mentioned in the post- and the areas of the mesh that will touch the skin blue- also the specific blue that is mentioned).

Looking at your number of posts, I'm guessing that you're new to this site and making custom content? If so, here is a brief description on the differences of meshes and textures as this may help you solve some problems in the future:

Meshes are the particular shape of the content that you are making. You can take the human body for example- the different body shapes that people are have a similar role to meshes.

Textures on the other hand are like the specific details that are etched on our body. They make up the colours of our hair, skin and eyes. Textures are 2D and provide only the pattern whereas meshes provide the shape. Therefor, when you import the edited mesh back into S4S, the shape of the character in the preview box will stay the same but the texture.