Drupal 8.x

Hi,
I Would like to send a note on Version upgrade from [Drupal 8.9.16,PHP 7.4, Mysql 5.7, Ubuntu 16.04] to [Drupal 8.9.16,PHP 7.4, Mysql 8.0.25, Ubuntu 20.04].
By using the New version, we had few conflicts in group module and that conflict was group is a reserved keyword. To mitigate the same, I had prefixed all tables in database and changed the settings accordingly. Post fix, I have an issue while login to the site and its redirect to Home page not to the user's page.

Can not update Drupal 9.1 to version 9.2 with my production site.

This error is displayed in the terminal :

[RuntimeException]
Could not delete /home/clients/b84eedfa06/sites/www.example.com/sites/default/default.services.yml:

I created a Views page with the email fields for user accounts. I want the "partners" role to be able to view this list.

My problem is that only the admin can see the emails. If I created a user with the role "partners", the email addresses are not displayed.

I don't want this role to have access to all email addresses. I want it to only access the email addresses on the Views page.

How do I display email addresses in a Views page ?

I have created a group and reached to members adding page. The displaying breadcrumb is below.

I have install group 8.x 1.3 module
Home > username >> Content >> Add >> Group membership

Proposed resolution

Id should be replaced with the group name.
Home > [Group name] >> Content >> Add >> Group membership

callBack
suddenly, on the live site I noticed that the callBacks are no longer executed.
I tried locally and the callBack code is executed.
I tried to change the name of the callBack and put an alert but it doesn't report any response.
I didn't understand what could have happened
I have controlalto and it no longer executes any callBack in any content Type
What tests can I do?

I'm trying to inspect the $variables that is available to a preprocess function, e.g.:

function mytheme_preprocess_node(&$variables) {
  debug($variables);
  ...
}

It doesn't work (site just crash).  Also tried dpm() and kint() with no luck. Google told me that others also struggle with this., but found nothing that actually worked.