How to reproduce:
1. Open attached Unity project "blacksmitenv2"
2. Load scene "bridge_small_02"

Expected Result: Game view is loaded properly without color changes.
Actual Result: Game view is distorted with the square of black and white parts.

Regression first introduced in: 5.6.0a1
Reproducible with: 5.6.0a1, 5.6.4f1, 2017.1.2f1, 2017.2.0a1
Not reproducible with: 5.5.5f1, 2017.2.0a2, 2017.2.0f3, 2017.3.0b3

Notes:
* When "The Blacksmith: Environments" Assets Pack is imported from the Assets Store, enter the play mode to see an issue.
* Squares with black/white parts are eliminated when disabling the "Bloom.cs" script, but smaller white/black parts still appear. In 5.6 version the same view (smaller white/black parts) is shown without disabling "Bloom.cs" script.
* Starting 2017.2.0a2 version there is no squares with black/white parts, but shader is broken (some parts become pink).
* In 5.5.5f1 version view is similar to 2017.2.0a2 and later, but there appear white parts instead of pink. This part is reproducible on AMD Radeon(TM) R5 Graphics GPU and is not reproducible on NVIDIA GeForce GTX 760 GPU.