Steps to reproduce:
1. Create a new project
2. Import the attached script "TestScript.cs"
3. Add the script to a camera
4. Enter Playmode

Result: crash

Reproduced on 5.6.0a1, 5.6.0f3, 2017.1.0a5
Not reproduced on 5.5.3f1

Notes:
-Does not appear to crash on Standalone build
-Workaround: use Destroy(RenderTexture) instead

The workaround in current project(with SpriteLightKit)

1. Deleting Library folder from your project
2. Go to your project Assets folder ---> SpriteLightKit folder
3. Open SpriteLightKit.cs and change UnityEngine.Object.DestroyImmediate( _texture ); to UnityEngine.Object.Destroy( _texture ); on line 149

Verified FIXED 2017.1.0b6, 5.6.1p2