Editor UI is not loading on upgrading a project from 2018.2 to 2018.3

Steps to Repro:
1. Create empty a project with 2018.2.0f2
2. Upgrade the project with 2018.3.0a5

Actual Result:
1. Unity opens with a black window

Note:
1. It's not occurring if the project is upgraded from 2018.1
2. Reopening the project brings back the UI

Environment:
Windows and Mac

Occurring with:
2018.3.0a6, 2018.3.0a5

Working with:
2018.3.0a4, 2018.3.0a1