I guess I find a spell errate here.

The highlight in the picture below, It's at Chapter 12 and <Password reset create action > section's Exercises. 
I guess you are trying to write "Submit an **invalid** email address" instead of "**valid**".

![image](https://user-images.githubusercontent.com/18417195/120591299-80b93480-c46e-11eb-98f7-b50109b3083c.png)

Anyway thanks again for the wonderful materials.