I am trying to adjust an edge in the UV editor (the one marked in red) and it lies behind another edge. The problem is in the 3D view without everything selected the UV map disappears in the UV editor. You can not just select a vertice, edge, or face in the 3d view and then work on it in the UV editor. What am I doing wrong?
Press this button on the UV/Image Editor window header
It never fails, it’s always just a button you don’t catch. Thanks Richard.