Blender black screen render I made a model of Harry Potter. but when  I render the model it's just a black screen.Duplication is on none. Seams to be nothing wrong with the node setup and render icon is checked on all the objects except the hair which I don't need to render. Thank you for taking the time to read this. Please help. 

link to the file
You have 2 mistakes.

1) You Muted Render layer In Node editor.

So go in Node editor, Compositing mode, select Render Layers Node and unmute it using M



2) You hide all objects in render. Click on camera icon to make them visible in render: