I am a complete beginner in creating CAS (Create-A-Sim) content, particularly clothing. While I have considerable experience in creating build and buy items, I am now focusing on learning how to create clothing items for The Sims 4. Currently, I am attempting to convert a top from The Sims 4, and I have received permission from the original creator to do so.

So far, the process has been going well, but I encountered an issue where one armpit of the top appears black, as if the sleeve is not properly connected to the rest of the garment. I am using mesh toolkit to assign bones, but I’m not sure what’s causing the problem or how to fix it. If anyone has insights or solutions regarding this issue, I would greatly appreciate your help!

you'll be likely to get answers if you post it in modding and creation

https://modthesims.info/f/593/

Okay, thank you!