Lack of information, no idea what it is, think it has something to with ShaderMixer so avoid it, etc etc, I could probably go on for several more lines about why nobody has answered, but I wont.
First thing is that this isn’t so much a “shader baker” it’s more of a texture baker, it burns the surface settings on your object onto a texture, and within the UV coordinates of the object.
The second thing is you only use lights if you want to burn specularity and/or shadows onto the texture, most of what I do with this is turning tileable textures into texture maps, so I usually “turn off” specularity (0% Gloss, black, 0% strength).
Third and probably the most important, is that it has it’s own render settings, and that you need to set them up for insane quality to get the best results, or as close to insane as this will allow, Max out Pixel Samples & shadow samples, and turn down the shading rate as far as it will go, all the way down to 0.10.
Then there is the finished texture size, no point in using a 600x600 map tiled 10 times and then putting it on a 2000x2000 texture, the larger the finished texture the better it will look.
Unless they have changed things it also only works as is with the default surface shader, you can get it to work with the shader mixer if you use the Baker brick in your shader, I’m not entirely sure but I think it also only works with the default DS lights, so things like UE2 and other shader based lights probably wont work.