Drupal 8.x

I`m using Bootstrap 4 theme and I have some users with diferents roles. I´ve used a dropdown menu of bootstrap and it only works when I sign in with admin account. 

With another account the following message appears in the console of my browser :

Uncaught TypeError: Bootstrap's dropdowns require Popper.js.

I don´t know what happen, if this is due to the user permissions or what.

Should I uninstall the "Update Manager" module when Drupal is installed with Composer ?

I installed Drupal 8 with Composer and in the update manager page the versions and modules are listed no matter what.

If I uninstall the module, in my dashboard there is an error indicating that the update manager needs to be installed.

The updates are managed by Composer, what is the use of this module and why does it display an error in the dashboard ?

In Drupal 7 you could create a context using panels so that you could pass contextual arguments through a URL to views blocks. I see no way to do that in Drupal 8.

Hi, almost every time I delete a field in my product types I get this message popping up in my dashboard :

<blockquote>ENTITY/FIELD DEFINITIONS
Mismatched entity and/or field definitions
The following changes were detected in the entity type and field definitions.
Product
The commerce_product.field_produit_labels field needs to be updated.</blockquote>

It has not been possible to update entities with "Drush" for some time.

Why do I have these problems regularly ? This is only with the Commerce module.

I have a D8.9.3 site. I want to update modules to D8/D9 compatible versions as they become available. Some D8 only modules are listed as "Up to date" but list a D8/D9 version as "Also Available" under the Available Updates "List" tab, however they are not listed under the "Update" tab.

If I attempt to install the new version over top, via Extend / Install New Module, I get an error that the module is already installed. If I try to uninstall the D8 only version first, I get a warning that all data will be lost.

How can I upgrade these modules without losing all data?

Hello,

I have 3 fields in a content type testimony :

- civility : field_civilite_interlocuteur (select list)

- Name : field_nom_interlocuteur (text)

- Function : field_fonction_interlocuteur (text)

In the field--field_nom_interlocuteur.html.twig template I'd like to concatenate fields to get something like :

Civility name, function.

I can't succeed to get value of other fields.

I try