Can't bake a simple cup for sketch fab I've been working in Blender for about 1.5 years now and I found a serious problem, that I cannot resolve myself.

The problem is Baking textures in Cycles Render mode (actually in every mode), which seems to bake a textures black and no shadows, colors, AO, nothing just black. Only normals and UVs bake shows something different and correct I guess. 

I tried many techniques to make it work somehow but neither of them tell me the right thing. I tried this and this.

They somehow seem useful but it still doesn't bake right. If you need my graphics info and Blender version: AMD Radeon R9 200 series Blender 2.78 Intel core i5-3470 CPU

So these are the steps I always followed:


Open a new project, set up a simple cube and a sunlight
In edit mode unwrap that cube using Smart UV Project.
Add a new image 512x512 without Blank option enabled
Then I made a new material in nodes editor (image bellow) with an
Image texture node connected to the Diffuse BSDF node. I kept the
image texture node selected and began baking, by clicking the Bake
button.
It didn't work so I even tried recalculating normals, making sure
it's not duplicated (the object) and checking if there aren't 2
materials active. I tried making a new project too but the probled
doesn't seem to go away.


Thank you for helping!

Here is link to file

https://drive.google.com/open?id=1_DkQR3JFfO14KWdWCL6uKS4eLWrKH-fu
You shouldn't have the wood image texture selected, when you do that a circular dependency is created, since you are trying to read the wood texture for use in baking and write to it at the same time. In fact, Blender warns you about this in the title bar:



What you should do is create another empty texture and select it to bake the texture onto: