Problem with Weight Paint

Hello, I have been having a problem with weight paint. I have an outer mesh, and an armature skeleton on in the inside which is parented as an object. I can bring the Mesh into weight paint and select the armature bones individually, However when i attempt to paint the mesh, nothing happens. What can i do to fix this, or what am I doing wrong?
The weight is set to 1, and the opacity is set to 1 as well.
Any help is appreciated, thanks

You need to add an Armature Modifier to the Mesh; an Object Parent doesn’t give access to the Bones for Deformation.