Not sure if this is regression or not - could be ...
This project works perfectly in 5.6.0p2, but in 2017.1.0b1 and b2 - the shadow of projectile or smoke or omething else is broken

How we can reproduce it using the example you attached
1 Create new project
2 Go to AssetStore and find "Tanks!!! Reference Project" (https://www.assetstore.unity3d.com/en/#!/content/80165)
3 Import this package to your project
- or use attached project -
4 Open LobbyScene and press Play
5 Press "Training", then "Start" and then "Start" again
6 Start shooting by clicking Left Mouse Button

Actual results: the shadow of projectile or smoke or omething else is broken and it shows big black circle - please see attached video and image in comments

Expected result: shadow should be ok