Please Help! Why is there a black line around my modeling?

Hello, I am a 3d modeler. My client informed me that there is a black line around the modeling.
Is this a texture issue? Can anybody tell me how I can fix this?

If this a develop issue can somebody tell me?
The client thinks it is because of catshadow / recieveshadow
Thank you so much. Please Help:(…

Are you able to share a test model that demonstrates the issue? It would be also important to see some code so it’s clear how material, renderer and objects are configured. Since you are a modeler, I guess it will be hard to provide a live example (three.js dev template - module - JSFiddle - Code Playground).

I’m afraid it is not possible to investigate the issue with just a screenshot.