The mesh glows strangely on the Sims 3 CAS mode.

Why?

and


Do you know about this gap as well?
There is a gap between the mesh and the sides.

Of course, the vertices and edges are not separated, but they are displayed so that the gaps can be seen as if they were separated in the game.

Do you know the cause?

Usually that strange glow in CAS mode disappear in Live mode. Some creators state that in their download posts..

Certainly, it will be cured on the Play mode.
Do you know the cause?

I have no background in meshing to tell what's exactly causing it, but I think it usually happens when a certain CAS item was modeled from a custom 3d mesh, instead of EA's default meshes. Maybe an experienced creator can elaborate this?

This happens when there's overlap of two different parts of the mesh in the UV Map. Usually people map the two sleeves in the same part of the texture to save space, which causes the glow. Sometimes it can be edited by remapping and fixing the textures; sometimes, when the item is too complex (usually when it has a translucent part or lots of meshed details), that's the only way the texture will fit in the right area, even if you use a 2048 texture.

As aisquared said, it will disappear in Live Mode. It's a courtesy to inform users about this glitch in the download page, but it's not something that will break the game.

Thanks you.

By the way, about the second image.
Do you know about the gaps between edges?

Could be clipping, could be a bone assignment mishap, but it's probably a very small gap between vertices or edges that was practically invisible on Milkshape or Blender when adjusting the mesh. In Blender, zoom on it really closely, activate the magnet icon, and snap one vertex/edge to the other.

That's a very small gap, though, and frills tend to be finicky in CC. It's up to you if you want to try to fix it, or release it as-is with a warning.