1) Views functionality was changed
Until 3.6 you could attach components to a view without switching to it:
dhxComponent.cells(id).view(name).attachMenu();
dhxComponent.cells(id).view(name).attachGrid();
dhxComponent.cells(id).view(name).setActive();
Starting from 4.0, firstly you need to show a view and then attach components to it:
// firstly make a view active
dhxComponent.cells(id).showView(name);
// then attach any components
dhxComponent.cells(id).attachMenu();
dhxComponent.cells(id).attachGrid();