[solved]Clothes mesh suddenly gains an extra unwanted slider

If you export .blend from Studio you will see that mesh was split right in the area where you have the spot. When you import the mesh Studio splits edges since game requires mesh to be split on the sides, sleeves, in the back. By default Studio knows where and how to split the mesh, but with this epaulette it doesn't know where to split and splits it in the middle of the accessory. In this case you need to split edges yourself, I recommend to split it this way. When you import and export again this mesh you won't see any shading (it is visible in Blender in solid view).