reinstalled all contribs with composer

need to run :
drush ev 'drupal_flush_all_caches();'
drush cr
and restart nginx and php-fpm before loading the website

web/themes/custom/edlptheme/templates/layout/region.html.twig

@@ -0,0 +1,25 @@
+{#
+/**
+ * @file
+ * Theme override to display a region.
+ *
+ * Available variables:
+ * - content: The content for this region, typically blocks.
+ * - attributes: HTML attributes for the region <div>.
+ * - region: The name of the region variable as defined in the theme's
+ *   .info.yml file.
+ *
+ * @see template_preprocess_region()
+ */
+#}
+{%
+  set classes = [
+    'region',
+    'region-' ~ region|clean_class,
+  ]
+%}
+{% if content %}
+  <div{{ attributes.addClass(classes) }}>
+    {{ content }}
+  </div>
+{% endif %}