I try to follow a project to learn mongoDB, Express...

But i'm blocked for the moment. Indeed, when i want to do a request on postman to update a user, i have this error (image) :

events.js:352 throw er; // Unhandled 'error' event

Repository Git of this project : https://github.com/l-jonathan/projet-mern

I'm trying a lot of solutions find on the web but nothing work, if you have an idea, i take it !

Thanks !