Reproduction steps:

1. Open the attached "Archive project"
2. Build and run it for iOS.
3. Rapidly touch the screen to reload the video for about 5-10 seconds( 4 - 8 touches per second) .
- Application crashes:

thread #11: tid = 0x59b73f, 0x0000000198070160 libobjc.A.dylib`objc_release + 16, name = 'UnityGfxDeviceWorker', stop reason = EXC_BAD_ACCESS (code=1, address=0x20)
frame #0: 0x0000000198070160 libobjc.A.dylib`objc_release + 16
frame #1: 0x000000018fcdcc8c MetalTools`-[MTLDebugRenderCommandEncoder .cxx_destruct] + 180
frame #2: 0x0000000198056b54 libobjc.A.dylib`object_cxxDestructFromClass(objc_object*, objc_class*) + 148
frame #3: 0x0000000198062080 libobjc.A.dylib`objc_destructInstance + 92

Regression introduced in:
5.6.0b6 or 5.6.0b5( Doesn't build in Xcode )

Reproduced with:
5.6.0b6
Metal
iPhone 6 iOS 9.0.2

Not reproducible with:
5.6.0b4
OpenGLES2

Note:
- If video doesn't play, reload all the assets in the Editor and attach the video file onto VideoPlayer game object.
- Application crashes on both Metal and OpenGLES2 in 5.6.0b4 with "Lost connection to" in Xcode on any speed reloads after 3-6 reloads.
- Full log in the edit.