Reproduction steps:
1. Download DOTSSample (https://github.com/Unity-Technologies/DOTSSample)
2. Open the project
3. Open scene "Whitebox_Arena_A"
4. Enter Play mode

Expected result: Play mode is entered without a crash, assertion failure or a freeze
Actual result: When entering Play mode, Editor might crash, freeze or produce an assertion failure

Reproducible with: 2020.1.0a26, 2020.2.0a1, 2020.2.0a9
Not reproducible with: 2019.3.6f1, 2019.3.12f1
Didn't test other versions due to inconsistent reproduction, varying behaviour and package errors

Stacktrace (when it crashes):
0x00007FF7C043CB63 (Unity) GfxDeviceD3D11Base::DrawBuffersBatchMode
0x00007FF7C3341F78 (Unity) GfxDeviceWorker::RunCommand
0x00007FF7C33459FC (Unity) GfxDeviceWorker::RunExt
0x00007FF7C3345DE8 (Unity) GfxDeviceWorker::RunGfxDeviceWorker
0x00007FF7C12818C0 (Unity) Thread::RunThreadWrapper
0x00007FFC6B1A7974 (KERNEL32) BaseThreadInitThunk
0x00007FFC6DEAA271 (ntdll) RtlUserThreadStart

Notes:
- "Assertion failed on expression: '0 == m_CurrentBufferBindMask[kUnityPerDraw]'" can appear on either entering or exiting Play mode in the mentioned scene
- Sometimes after exiting the scene and trying to close the Editor, it freezes on loading and produces this error in the Editor log once the process has been killed:
AcceleratorClientConnectionCallback - disconnected - :0
Cleanup mono
Culling group was not disposed. You have to call Dispose explicitly from the main thread. This will likely result in a crash.
(Filename: C:\buildslave\unity\build\Runtime\Export\Camera\CullingGroup.bindings.cpp Line: 70)