Hey guys I see you have lighting troubles…
I was working on survival shooter series when I encountered this lighting problem after reloading the level ie (after game over) the lights become suddenly dim and the scene looked like a trash after reloading.
But after a long time I found a solution
Solution : Find menu bar and
Window → Lighting and there you get a dialog box you will observe auto written write next to the check box on down right, uncheck that checkbox you will also notice a drop down menu ( combobox) on its right on which build is written click on it and you will notice that it will extract all the lighting data on your scene now
When you play your game it works as it is intended. hope this helps to someone.
Apparently, this is caused by the new lighting system (called Enlighten) that was introduced with Unity 5.
To quote, the problem and solution are as follows:
In Unity 5, Enlighten will try and automatically bake anything marked static, like our environment here. Currently these meshes don’t all have valid Lightmap UVs for Enlighten to bake to as the project wasn’t initially intended for baking, so you get these weird black areas of overlaps and repeats.
If you go to the project’s models folder, select each environment and prop mesh and tick Generate Lightmap UV’s in the asset’s Inpsector Model tab, wait for Unity to create some valid UV’s, then let Enlighten rebake, then you shouldn’t see these weird errors anymore (hopefully!)