How to reproduce:
1. Open Unity
2. Load tester-submitted project(Particles.zip)
3. Open '1.unity' scene
4. Select 'Particle System'
5. Expand material component.
6. Run the scene while observing material properties in Inspector(Repeat this step until issue occurs

Expected result: Particle System is destroyed without any issues and messages in Console
Actual result: Particle System is destroyed with some cosmetic MissingReferenceException errors being thrown in the Console

Notes:

• Reproduction probability varies between different machines.
• Typically reproduces within 10 attempts.
• The issue seems to be related to VertexStreams but altering Vertex Streams options in Particle System seems to not affect the problem.

Reproducible with - 2017.3.0f3, 2018.1.0a7
Could not test: 5.6.4p4, 2017.1.2p4, 2017.2.1p1, 2017.3.0a1('Particles/Standard Unlit' shader has not yet been introduced)

Verified in: 2018.2.0a7