I have a problem with baking - "No active UV layer found" As you can see in my screenshot im having trouble baking a texture for Ambient Occlusion. I  already added a new image and smart uv unwrapped my low poly mesh "rock_lp". It is the second one i selected, so its the active one. The other one is the high poly version. When i try to bake, I get the error "No active UV layer found in the object rock_hp". What does this mean? Is there something i forgot to do? 



PS: I already added a new image after doing retopology on the low poly mesh so that was ok I believe.
Your high poly one is the one active, which explain the error you are getting about the UVs for your high poly mesh. Just reselect them and you should be fine.