The problem happens when you use Shadergraph and NUnit packages together with enabled Cache Server.
Also it reproduces only when there are 2 specific shadergraph files are in the project

2. How we can reproduce it:
1 Create new project using 2019.3.0b5
2 Add 2 attached "shadergraph" files (or use attached project)
3 Add Shadergraph package through Package Manager
4 Make sure that you doesn't have NUnit package installed for your project (Most probably you have it, so remove it through Package Manager including all other packages that depend on it)
5 Enable Cache Server in Editor Preferences (you need to have Accelerator installed)
6 Close Editor
7 Delete Library folder
8 Open project in the Editor again
9 Go to Package Manager and install NUnit package
10 Close the Editor
11 Delete Library folder (Note: you shouldn't clear Cache folder of Cache Server)
12 Open project in the Editor again
Actual results: Editor crashes on opening project
(Note: if you disable Cache Server or clear Cache folder - project will start opening fine)