Steps to reproduce:
1. Create a new project and launch in DirectX 12 mode
2. Create a Light Probe Group
3. Select create a Light Probe Group game object

Results: In 5-10 seconds Editor will crash.

Reproduced with: 2019.3.0a6, 2019.2.0b6, 2019.1.7f1
Not reproducible with: 2018.4.2f1
Regression introduced in: 2019.2.0a7, 2019.1.0b7

Note:
- The issue was tested with DX11, Vulkan and was not reproduced.
- In 2019.1 Editor freezes

========== OUTPUTTING STACK TRACE ==================

0x00007FF720F100F8 (Unity) D3D12ScratchBuffer::D3D12ScratchBuffer
0x00007FF720F16854 (Unity) D3D12CommandList::ReserveScratchMemory
0x00007FF720ED6226 (Unity) D3D12DynamicVBOScratchMemory::Reserve
0x00007FF72179BDF9 (Unity) DynamicVBOBufferManager::AcquireSharedInternal
0x00007FF72179E23B (Unity) DynamicVBO::GetChunk
0x00007FF72179E06B (Unity) DynamicVBO::GetChunk
0x00007FF7206C91C3 (Unity) DrawImmediate::BeginBuffer
0x00007FF7206C90E7 (Unity) DrawImmediate::Begin
0x00007FF720F4681F (Unity) GfxDeviceWorker::RunCommand
0x00007FF720F4CCBB (Unity) GfxDeviceWorker::RunExt
0x00007FF720F4D0A8 (Unity) GfxDeviceWorker::RunGfxDeviceWorker
0x00007FF721D7C7F7 (Unity) Thread::RunThreadWrapper
0x00007FFDCEDF7974 (KERNEL32) BaseThreadInitThunk
0x00007FFDD00FA271 (ntdll) RtlUserThreadStart

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

Fixed in: 2019.3.0a9