[Unity 5] weird lighting issue when baking.

After lots of time spent getting my lighting the way I liked it in Unity 5, I come across this issue with most of my models. Whenever I bake the lighting, this always happens to them:

64767-weird-lighting-issue.png

As you can see there are weird black bars around certain faces of the models. Also the image was brightened to see the problem better.

Any help would be appreciated!

PS: I don’t think this is related to the bake settings, as it doesn’t happen with some models.

I feel so stupid, yes, ticking “Generate Lightmap UVS” worked. I had to bake the lighting again. Thank you to everyone that helped.