To reproduce:
1. Create a new scene.
2. Create a new Particle System.
3. Type "Infinity" in start lifetime.
4. Stop and Play again Particle Effect in scene window.
5. Observe the console log.
6. Play the scene.
7. Observe the console log.

Expected result: no errors.
Actual result: Errors in a console.

Reproducible: 2017.3.0a6, 2017.3.0f1, 2018.1.0a6
Not reproducible: 2017.2.0p4, 2017.3.0a5 (because Start Lifetime is capped at 100 000)

Note:
When Start Lifetime is changed from a script, it will start producing errors only when ParticleSystem is stopped and played again.