For me, whenever I click on the Collision view, it crashes the entire editor. My version is 4.20.3. Does this happen to anyone else? If so, does anyone have a way to resolve this?
Watch video 88 : Resetting your unreal project it might help you (from the original course, without the reworked content)
@Batyu, I decided to give this one more try before looking ahead (Resetting Your Unreal Project is actually 2 or 3 videos ahead of me – Line Tracing). Here are the steps I tried:
Compile the code. No issues. 
Build the game (via “Build” at the top). No issues.
Click Lit > Player Collision. It works!
The ONLY thing I can think of that is different between now and the initial posting 4 days ago is that my laptop is plugged in now. I can’t remember if it was at the time. When it’s plugged in, I believe it’s in a sort of “High Performance” mode.
Anywho, for documentation’s sake, I figured I’d share all this here. Hopefully it helps someone else.