Drupal 8.x

On drupal 8/9 I would like to:

1. upload files to the private folder 
2. allow only authenticated users to view the file with the direct link

Ideally, I would like to control that access by role but i'll settle for 2.

After a lot of googling and reading documentation, I am getting the impression this is not possible in Drupal 8. 

Could someone give me a definitive answer on this? I always assumed the above was one of the basic purposes of private files but... clearly not. 

Here's what's happening.

When i click to view a user profile the link looks like for example:

website.com/user

Then when i click the home button it will go to

website.com/user/home

And since the link doesn't exist i get a page not found error when it should go back to the home page

website.com

using drupal 8...any help would be appreciated

On a separate note, haven't upgraded to drupal 9, because it uses mysql server version 5.7 which is not supported by

I had a week-old Drupal 9.3.7 site. I added some content, I installed some contributed modules. No problems worth mentioning. Then, I installed the Devel module. No apparent problem, at first sight.

Everything was running fine until I tried to install ng_lightbox (this resulted in an Error 500) and now I get:

Fatal error: Cannot redeclare at_tools_preprocess_system_themes_page() (previously declared in /var/www/html/drupal/modules/at_tool/at_tool.module:21) in /var/www/html/drupal/modules/at_tools/at_tools.module on line 21

but only when logged in.

The site itself still works.

We're trying to add a 'class' field to the media library CKEditor edit form using the code from the Media Library module docs: