Reproduction steps:
1. Open the attached project;
2. Open the scene "0";
3. Drag the scenes "1", "2", "3" and "4" to the scene;
4. Open Lighting window and click "Generate Lighting";

Actual result: some scenes become white (generate_lighting.jpg).
Expected result: the lighting should be generated normally (auto_generate.jpg).

Note: if "Auto Generate" is selected, the generated scenes look correctly. When the Play mode is turned on, the scenes become normal. Also, when you are selecting the active scene, the information in Lighting window does not change according to the active scene.

Reproduced with: 5.5.0a6, 5.5.0f1, 5.6.0f2, 2017.1.0a4
Not reproducible with: 5.4.5p1
Regression introduced in 5.5.0a