How to reproduce:
1. Open attached project
2. Enter play mode
3. Press '6' and wait for a few minutes (Pressing 6 sets Time.timeScale = 20;)

Reproduced on: 5.5.0f1, 5.5.3p2, 5.6.0a2
Not reproduced on: 5.6.0a3, 5.6.0p3, 2017.1.0b3

========== OUTPUTING STACK TRACE ==================

0x0000000140B60A7B (Unity) CalculateSkinPoseMathLib<4>
0x0000000140D6E2A9 (Unity) CalculateVertexData
0x0000000140D713F8 (Unity) GetPositionMesh<1,1>
0x0000000140D77DC9 (Unity) ShapeModule::Start
0x0000000140DFACD0 (Unity) ParticleSystem::StartModules
0x0000000140DFFE58 (Unity) ParticleSystem::StartParticles
0x0000000140E005D1 (Unity) ParticleSystem::Update1Incremental
0x0000000140E0365E (Unity) ParticleSystem::Update1
0x0000000140E07720 (Unity) ParticleSystem::UpdateFunction
0x0000000140BEB395 (Unity) JobQueue::Exec
0x0000000140BEB5E8 (Unity) JobQueue::ExecuteJobFromHighPriorityStack
0x0000000140BEB7A8 (Unity) JobQueue::ProcessJobs
0x0000000140BEB89B (Unity) JobQueue::WorkLoop
0x0000000141013D7C (Unity) Thread::RunThreadWrapper
0x00007FFE6AFB8364 (KERNEL32) BaseThreadInitThunk
0x00007FFE6D4C70D1 (ntdll) RtlUserThreadStart

========== END OF STACKTRACE ===========

Fixed in: 2017.2.0a3
Backported to: 5.5.4p1, 5.6.1p4, 2017.1.0a10