Hey!
I am using Unity 5.0.0, and when my scene is baking, it looks the way it is supposed to, but when the bake finishes, it looks a lot weird. Is it an Engine bug or am I doing something wrong? How can I fix it?
Thanks in advance 
In the attachments, as you might guess, unitygiprob1.png is the screenshot while baking. And unitygiprob2.jpg is the one after baking.
Your first image shows a lot of light leaking around the edges of your geometry at the end of the corridor. I’m guessing that while this looks like an interesting effect, it’s not supposed to be happening. A light leak occurs when your geometry doesn’t quite “close”, which is to say that one edge doesn’t exactly meet another edge. That might be because of the way you modeled, or because of the accuracy of the modeling tool or of Unity. For example, if the floor is at 1.0003 along the Y axis but the wall starts at 1.0020, you wouldn’t be able to see that tiny gap but in maths terms they still don’t meet and perhaps Unity is interpreting it as a gap to send light through. If you fix that, you might find the odd light baking effect disappears too, but it’s hard to tell.
I had the same problem. You should check if you have enabled the “Generate Light Map” or “Generate UV Map” ( I do not remember very well) in the model importer inspector. This should fix your problem. Let me know if this advice has been helpful to you!