How to reproduce:
1. Create new project using HDRP template
2. Go to Edit -> Project Settings -> Player and under Other settings uncheck "Auto Graphics API Windows"
3. Add Vulcan Graphics API and move it up the column (So it is first)
4. Under Vulkan Settings check "Vulkan Editor Support (Experimental)" box
5. Open Look Dev by going Window -> Experimental -> Look Dev
6. Close Look Dev window
7. If Unity doesn't crash by this point try docking Look Dev window

Rerpoducible with: 2018.2.0b8, 2018.3.0a1
Not reproducible with: 2017.x versions and 2018.1.x versions (Vulkan editor support was added in 2018.2)