Steps to reproduce:
1. Open the project attached by the user

Expected result: Project is opened
Actual result: "Fatal error!" window is shown and after pressing "Quit" Unity crashes

Reproducible with: 2019.2.0a11, 2019.2.10f1, 2019.3.0b4, 2019.3.0b8
Not reproducible with: 2017.4, 2018.4, 2019.2.0a10, 2019.3.0b3, 2020.1

Notes:
- On 2019.3 stream instead of "Fatal error!" window, "Failed to load window layout" window is shown
- If Inspector window is closed in a version where the bug is not reproducible and then the project is upgraded to a version where the bug is reproducible, the project will be opened, but there will be a black space on the right side of the editor (where the Inspector would normally be) and NullReferenceException spammed. The same outcome can be reached by deleting the ProjectSettings window.