Steps to reproduce the issue:
1. Download and open attached project on Mac.
2. When the project is loaded, quickly double-click on the "Scripts" folder inside of the "Project" window.

Actual result:
The Editor crashes.

Expected result:
The Editor should not crash.

Reproduced with:
5.1.5f1, 5.2.5f1, 5.3.5f1, 5.3.6f1, 5.4.0f3.
5.5.0a5 ("Unity quit unexpectedly" window appears when trying to load a project).

Note1:
The issue is not reproducible when the 2nd step is performed after some time, but not immediately.

Note2:
GIF attached.