So I'm loading my parent object that has a child a SkinnedMesh (blue jacket in the first picture) and I'm trying to replace it with another object that is a Mesh (red jacket in the second picture). After all my tries I got stuck with this result:

First picture

Second picture

Here's the code where I'm trying to do it:

loader.load( `./objects/Idle.fbx`, function ( object )
{
         object.traverse( function ( child ) 
         {
                if ( child.isMesh ) 
                {
                    if (child.name=="jacket")
                    {
                        loader.load( './objects/jacket2.fbx', function( object2 )
                        {
                            object2.traverse( function (child2)
                            {
                                if (child2.isMesh)
                                {
                                    child.geometry = child2.geometry;
                                    child.material = child2.material;
                                    child.material.skinning=true;
                                    child.verticesNeedUpdate = true;
                                }
                            }
                        }
                    }
                }
            }
}