Reproduction Steps:
1. Open project
2. In Hierarchy select "Particle System/SubEmmitterBirth/SubEmmitterBirth"
3. Under Particle System Component enable Sub Emitters
4. Click on the Particle System field
5. Select "Particle System/SubEmmitterBirth" (its parent)
6. It should Crash now

Note: First and second (in this case "Particle System" and ""Particle System/SubEmmitterBirth") levels are handled and throws error "Circular References Detected" if their parent or them themselves are selected.

Expected behaviour: All levels of Sub Emitters throw error if Circular References are used.
Actual result: Only the first two levels throw this error all other crashes.

Reproduced on versions: Unity 5.5.0f1, 5.5.0p1, 5.6.0a1, 5.6.0b1
Did not reproduce on versions: Unity 5.3.7p2, 5.4.3p3, 5.5.0b11
Regression introduce in Unity 5.5.0f1