Howard Miller

I'm unsure why you are concerned? That's just one of the normal upgrade pages.

 

Click the button that says, "Upgrade database now"

slim is a new thing added in 4.5 and I know next to nothing about it. My understanding is that this is mostly to support routing. That begs the question if you did anything related to this admin documentation...

Configuring_the_Router

In the nicest way... you're sounding a bit like someone who has been asked to sort a Moodle problem without ever having seen Moodle.

It's possible to configure Moodle to use email addresses as a username. But I don't think that's what you're asking. I'm not sure what you are asking.

Moodle doesn't (really) have file sharing for ordinary users. It's not what it's for or does. So, again, I'm struggling to understand what your concern is.

A user can change their (own) email visibility in their profile settings.

I'm never completely sure if I'm being insulted, or not