diff --git a/app/assets/stylesheets/helpers.scss b/app/assets/stylesheets/helpers.scss
index de1fff1ed..92755dac9 100644
--- a/app/assets/stylesheets/helpers.scss
+++ b/app/assets/stylesheets/helpers.scss
@@ -28,3 +28,7 @@
   display: inline-block;
   width: 5px;
 }
+
+.text-center {
+  text-align: center;
+}
diff --git a/app/controllers/concerns/create_avis_concern.rb b/app/controllers/concerns/create_avis_concern.rb
index a76c03f01..9854ec405 100644
--- a/app/controllers/concerns/create_avis_concern.rb
+++ b/app/controllers/concerns/create_avis_concern.rb
@@ -9,7 +9,8 @@ module CreateAvisConcern
     # the :emails parameter is a 1-element array.
     # Hence the call to first
     # https://github.com/rails/rails/issues/17225
-    expert_emails = create_avis_params[:emails].first.split(',').map(&:strip)
+    expert_emails = create_avis_params[:emails].presence || [].to_json
+    expert_emails = JSON.parse(expert_emails).map(&:strip).map(&:downcase)
     allowed_dossiers = [dossier]
 
     if create_avis_params[:invite_linked_dossiers].present?
@@ -65,6 +66,6 @@ module CreateAvisConcern
   end
 
   def create_avis_params
-    params.require(:avis).permit(:introduction_file, :introduction, :confidentiel, :invite_linked_dossiers, emails: [])
+    params.require(:avis).permit(:introduction_file, :introduction, :confidentiel, :invite_linked_dossiers, :emails)
   end
 end
diff --git a/app/controllers/instructeurs/dossiers_controller.rb b/app/controllers/instructeurs/dossiers_controller.rb
index 7ce205c9c..74930bfcb 100644
--- a/app/controllers/instructeurs/dossiers_controller.rb
+++ b/app/controllers/instructeurs/dossiers_controller.rb
@@ -60,6 +60,7 @@ module Instructeurs
     def avis
       @avis_seen_at = current_instructeur.follows.find_by(dossier: dossier)&.avis_seen_at
       @avis = Avis.new
+      @experts_emails = dossier.procedure.experts_procedures.where(revoked_at: nil).map(&:expert).map(&:email).sort
     end
 
     def personnes_impliquees
diff --git a/app/controllers/new_administrateur/experts_procedures_controller.rb b/app/controllers/new_administrateur/experts_procedures_controller.rb
new file mode 100644
index 000000000..1b965f0dc
--- /dev/null
+++ b/app/controllers/new_administrateur/experts_procedures_controller.rb
@@ -0,0 +1,43 @@
+module NewAdministrateur
+  class ExpertsProceduresController < AdministrateurController
+    before_action :retrieve_procedure, only: [:add_expert_to_procedure, :revoke_expert_from_procedure]
+
+    def add_expert_to_procedure
+      emails = params['emails'].presence || [].to_json
+      emails = JSON.parse(emails).map(&:strip).map(&:downcase)
+
+      valid_users, invalid_users = emails
+        .map { |email| User.create_or_promote_to_expert(email, SecureRandom.hex) }
+        .partition(&:valid?)
+
+      if invalid_users.any?
+        flash[:alert] = invalid_users
+          .filter { |user| user.errors.present? }
+          .map { |user| "#{user.email} : #{user.errors.full_messages_for(:email).join(', ')}" }
+      end
+
+      if valid_users.present?
+        valid_users.each do |user|
+          experts_procedure = ExpertsProcedure.find_or_create_by(expert: user.expert, procedure: @procedure)
+          if !experts_procedure.revoked_at.nil?
+            experts_procedure.update!(revoked_at: nil)
+          end
+        end
+
+        flash[:notice] = t('.experts_assignment',
+          count: valid_users.count,
+          value: valid_users.map(&:email).join(', '),
+          procedure: @procedure.id)
+      end
+      redirect_to admin_procedure_invited_expert_list_path(@procedure)
+    end
+
+    def revoke_expert_from_procedure
+      expert_procedure = ExpertsProcedure.find_by!(procedure: @procedure, id: params[:expert_procedure][:id])
+      expert_email = expert_procedure.expert.email
+      expert_procedure.update!(revoked_at: Time.zone.now)
+      flash[:notice] = "#{expert_email} a été révoqué de la démarche et ne pourra plus déposer d'avis."
+      redirect_to admin_procedure_invited_expert_list_path(@procedure)
+    end
+  end
+end
diff --git a/app/controllers/new_administrateur/procedures_controller.rb b/app/controllers/new_administrateur/procedures_controller.rb
index 8b2c0431d..212878085 100644
--- a/app/controllers/new_administrateur/procedures_controller.rb
+++ b/app/controllers/new_administrateur/procedures_controller.rb
@@ -186,7 +186,8 @@ module NewAdministrateur
     end
 
     def invited_expert_list
-      @experts_procedure = @procedure.experts_procedures.sort_by { |expert_procedure| expert_procedure.expert.email }
+      @experts_procedure = @procedure.experts_procedures.where(revoked_at: nil).sort_by { |expert_procedure| expert_procedure.expert.email }
+      @experts_emails = experts_procedure_emails
     end
 
     def update_allow_decision_access
@@ -198,6 +199,10 @@ module NewAdministrateur
 
     private
 
+    def experts_procedure_emails
+      @procedure.experts.map(&:email).sort
+    end
+
     def apercu_tab
       params[:tab] || 'dossier'
     end
diff --git a/app/controllers/users/dossiers_controller.rb b/app/controllers/users/dossiers_controller.rb
index f77eff7ab..f03d28f19 100644
--- a/app/controllers/users/dossiers_controller.rb
+++ b/app/controllers/users/dossiers_controller.rb
@@ -360,12 +360,12 @@ module Users
 
       if champs_params[:dossier]
         @dossier.assign_attributes(champs_params[:dossier])
-        # FIXME in some cases a removed repetition bloc row is submitted.
-        # In this case it will be trated as a new records and action will fail.
+        # FIXME: in some cases a removed repetition bloc row is submitted.
+        # In this case it will be treated as a new record, and the action will fail.
         @dossier.champs.filter(&:repetition?).each do |champ|
           champ.champs = champ.champs.filter(&:persisted?)
         end
-        if @dossier.champs.any?(&:changed?)
+        if @dossier.champs.any?(&:changed_for_autosave?)
           @dossier.last_champ_updated_at = Time.zone.now
         end
         if !@dossier.save
diff --git a/app/models/champ.rb b/app/models/champ.rb
index 864ced9fb..8cb1d8804 100644
--- a/app/models/champ.rb
+++ b/app/models/champ.rb
@@ -18,7 +18,7 @@
 #  type_de_champ_id               :integer
 #
 class Champ < ApplicationRecord
-  belongs_to :dossier, -> { with_discarded }, inverse_of: :champs, touch: true, optional: false
+  belongs_to :dossier, -> { with_discarded }, inverse_of: false, touch: true, optional: false
   belongs_to :type_de_champ, inverse_of: :champ, optional: false
   belongs_to :parent, class_name: 'Champ', optional: true
   has_many :commentaires
diff --git a/app/models/dossier.rb b/app/models/dossier.rb
index aaf93e14f..2441035f0 100644
--- a/app/models/dossier.rb
+++ b/app/models/dossier.rb
@@ -65,8 +65,8 @@ class Dossier < ApplicationRecord
   has_one_attached :justificatif_motivation
   has_one_attached :pdf_export_for_instructeur
 
-  has_many :champs, -> { root.public_ordered }, inverse_of: :dossier, dependent: :destroy
-  has_many :champs_private, -> { root.private_ordered }, class_name: 'Champ', inverse_of: :dossier, dependent: :destroy
+  has_many :champs, -> { root.public_ordered }, inverse_of: false, dependent: :destroy
+  has_many :champs_private, -> { root.private_ordered }, class_name: 'Champ', inverse_of: false, dependent: :destroy
   has_many :commentaires, inverse_of: :dossier, dependent: :destroy
   has_many :invites, dependent: :destroy
   has_many :follows, -> { active }, inverse_of: :dossier
diff --git a/app/models/experts_procedure.rb b/app/models/experts_procedure.rb
index 203f927fc..438086376 100644
--- a/app/models/experts_procedure.rb
+++ b/app/models/experts_procedure.rb
@@ -4,6 +4,7 @@
 #
 #  id                    :bigint           not null, primary key
 #  allow_decision_access :boolean          default(FALSE), not null
+#  revoked_at            :datetime
 #  created_at            :datetime         not null
 #  updated_at            :datetime         not null
 #  expert_id             :bigint           not null
diff --git a/app/models/export.rb b/app/models/export.rb
index 208b68df3..ef521e01e 100644
--- a/app/models/export.rb
+++ b/app/models/export.rb
@@ -4,7 +4,7 @@
 #
 #  id         :bigint           not null, primary key
 #  format     :string           not null
-#  key        :text
+#  key        :text             not null
 #  created_at :datetime         not null
 #  updated_at :datetime         not null
 #
diff --git a/app/views/experts/shared/avis/_form.html.haml b/app/views/experts/shared/avis/_form.html.haml
index a1bcf1fac..a8ec6a80c 100644
--- a/app/views/experts/shared/avis/_form.html.haml
+++ b/app/views/experts/shared/avis/_form.html.haml
@@ -1,30 +1,38 @@
-%section.ask-avis
-  %h1.tab-title Inviter des personnes à donner leur avis
-  %p.avis-notice Les invités pourront consulter le dossier, donner un avis et contribuer au fil de messagerie. Ils ne pourront pas modifier le dossier.
+- if @dossier.procedure.feature_enabled?(:admin_affect_experts_to_avis).blank?
+  %section.ask-avis
+    %h1.tab-title Inviter des personnes à donner leur avis
+    %p.avis-notice Les invités pourront consulter le dossier, donner un avis et contribuer au fil de messagerie. Ils ne pourront pas modifier le dossier.
 
-  = form_for avis, url: url, html: { class: 'form' } do |f|
-    = f.email_field :emails, placeholder: 'Adresses email, séparées par des virgules', required: true, multiple: true, onchange: "javascript:DS.replaceSemicolonByComma(event);"
-    = f.text_area :introduction, rows: 3, value: avis.introduction || 'Bonjour, merci de me donner votre avis sur ce dossier.', required: true
-    %p.tab-title Ajouter une pièce jointe
-    .form-group
-      = text_upload_and_render f, avis.introduction_file
+    = form_for avis, url: url, html: { class: 'form' } do |f|
+      - hidden_field_id = SecureRandom.uuid
+      = hidden_field_tag  'avis[emails]', nil, data: { uuid: hidden_field_id }
+      = react_component("ComboMultipleDropdownList",
+          options: [],
+          selected: [], disabled: [],
+          hiddenFieldId: hidden_field_id,
+          label: 'avis_emails',
+          acceptNewValues: true)
+      = f.text_area :introduction, rows: 3, value: avis.introduction || 'Bonjour, merci de me donner votre avis sur ce dossier.', required: true
+      %p.tab-title Ajouter une pièce jointe
+      .form-group
+        = text_upload_and_render f, avis.introduction_file
 
-    - if linked_dossiers.present?
-      = f.check_box :invite_linked_dossiers, {}, true, false
-      = f.label :invite_linked_dossiers, t('helpers.label.invite_linked_dossiers', count: linked_dossiers.length, ids: linked_dossiers.map(&:id).to_sentence)
+      - if linked_dossiers.present?
+        = f.check_box :invite_linked_dossiers, {}, true, false
+        = f.label :invite_linked_dossiers, t('helpers.label.invite_linked_dossiers', count: linked_dossiers.length, ids: linked_dossiers.map(&:id).to_sentence)
 
-    .flex.justify-between.align-baseline
-      - if must_be_confidentiel
-        %p.confidentiel.flex
-          %span.icon.lock
-          %span
-            Cet avis sera confidentiel : il ne sera pas affiché aux autres experts consultés, mais sera visible par les instructeurs.
+      .flex.justify-between.align-baseline
+        - if must_be_confidentiel
+          %p.confidentiel.flex
+            %span.icon.lock
+            %span
+              Cet avis sera confidentiel : il ne sera pas affiché aux autres experts consultés, mais sera visible par les instructeurs.
 
-      - else
-        .confidentiel-wrapper
-          = f.label :confidentiel, 'Cet avis sera '
-          = f.select :confidentiel, [['partagé avec les autres experts', false], ['confidentiel', true]], {}, onchange: "javascript:DS.toggleCondidentielExplanation(event);"
-          .confidentiel-explanation.hidden
-            Il ne sera pas affiché aux autres experts consultés, mais sera visible par les instructeurs.
+        - else
+          .confidentiel-wrapper
+            = f.label :confidentiel, 'Cet avis sera '
+            = f.select :confidentiel, [['partagé avec les autres experts', false], ['confidentiel', true]], {}, onchange: "javascript:DS.toggleCondidentielExplanation(event);"
+            .confidentiel-explanation.hidden
+              Il ne sera pas affiché aux autres experts consultés, mais sera visible par les instructeurs.
 
-    = f.submit 'Demander un avis', class: 'button primary send'
+      = f.submit 'Demander un avis', class: 'button primary send'
diff --git a/app/views/instructeurs/shared/avis/_form.html.haml b/app/views/instructeurs/shared/avis/_form.html.haml
index a1bcf1fac..466b48c66 100644
--- a/app/views/instructeurs/shared/avis/_form.html.haml
+++ b/app/views/instructeurs/shared/avis/_form.html.haml
@@ -1,9 +1,22 @@
 %section.ask-avis
   %h1.tab-title Inviter des personnes à donner leur avis
   %p.avis-notice Les invités pourront consulter le dossier, donner un avis et contribuer au fil de messagerie. Ils ne pourront pas modifier le dossier.
+  - if @dossier.procedure.feature_enabled?(:admin_affect_experts_to_avis)
+    %p.avis-notice Choisissez des experts à qui vous souhaitez demander un avis parmi la liste prédéfinie par les administrateurs de la démarche
+  - else
+    %p.avis-notice Entrez les adresses email des experts à qui vous souhaitez demander un avis
 
   = form_for avis, url: url, html: { class: 'form' } do |f|
-    = f.email_field :emails, placeholder: 'Adresses email, séparées par des virgules', required: true, multiple: true, onchange: "javascript:DS.replaceSemicolonByComma(event);"
+    - hidden_field_id = SecureRandom.uuid
+    = hidden_field_tag  'avis[emails]', nil, data: { uuid: hidden_field_id }
+    = react_component("ComboMultipleDropdownList",
+        options: @dossier.procedure.feature_enabled?(:admin_affect_experts_to_avis) ? @experts_emails : [],
+        selected: [],
+        disabled: [],
+        hiddenFieldId: hidden_field_id,
+        label: 'avis_emails',
+        id: 'avis_emails',
+        acceptNewValues: @dossier.procedure.feature_enabled?(:admin_affect_experts_to_avis).blank?)
     = f.text_area :introduction, rows: 3, value: avis.introduction || 'Bonjour, merci de me donner votre avis sur ce dossier.', required: true
     %p.tab-title Ajouter une pièce jointe
     .form-group
diff --git a/app/views/new_administrateur/procedures/invited_expert_list.html.haml b/app/views/new_administrateur/procedures/invited_expert_list.html.haml
index 2d894e5b3..3272948d4 100644
--- a/app/views/new_administrateur/procedures/invited_expert_list.html.haml
+++ b/app/views/new_administrateur/procedures/invited_expert_list.html.haml
@@ -5,12 +5,35 @@
 
 .container
   %h1.page-title.mt-2 Experts invités sur #{@procedure.libelle}
+
+  .container.groupe-instructeur
+
+    .card
+      .card-title Affecter des experts à la démarche
+      = form_for :experts_procedure,
+        url: admin_procedure_add_expert_to_procedure_path(@procedure),
+        html: { class: 'form' } do |f|
+
+        .instructeur-wrapper
+          %p.notice Pendant l'instruction d'un dossier, les instructeurs peuvent demander leur avis à un ou plusieurs experts.
+          %p.notice Entrez les adresses email des experts que vous souhaitez affecter à cette démarche
+          - hidden_field_id = SecureRandom.uuid
+          = hidden_field_tag :emails, nil, data: { uuid: hidden_field_id }
+          = react_component("ComboMultipleDropdownList",
+            options: [],
+            selected: [], disabled: [],
+            hiddenFieldId: hidden_field_id,
+            label: 'email expert',
+            acceptNewValues: true)
+
+          = f.submit 'Affecter à la démarche', class: 'button primary send'
   - if @experts_procedure.present?
     %table.table.mt-2
       %thead
         %tr
           %th Liste des experts
-          - if @procedure.feature_enabled?(:make_experts_notifiable)
+          %th Nombre d'avis
+          - if @procedure.feature_enabled?(:admin_affect_experts_to_avis)
             %th Notifier des décisions sur les dossiers
       %tbody
         - @experts_procedure.each do |expert_procedure|
@@ -18,8 +41,10 @@
             %td
               %span.icon.person
               = expert_procedure.expert.email
-            - if @procedure.feature_enabled?(:make_experts_notifiable)
-              %td
+            %td.text-center
+              = expert_procedure.avis.count
+            - if @procedure.feature_enabled?(:admin_affect_experts_to_avis)
+              %td.text-center
                 = form_for expert_procedure,
                   url: admin_procedure_update_allow_decision_access_path(expert_procedure: expert_procedure),
                   remote: true,
@@ -31,6 +56,12 @@
                     %span.toggle-switch-control.round
                     %span.toggle-switch-label.on
                     %span.toggle-switch-label.off
+            %td.actions= button_to 'retirer',
+              { action: "revoke_expert_from_procedure", :controller=>"new_administrateur/experts_procedures" },
+              { method: :put,
+                data: { confirm: "Êtes-vous sûr de vouloir révoquer l'expert « #{expert_procedure.expert.email} » de la démarche #{expert_procedure.procedure.libelle} ? Les instructeurs ne pourront plus lui demander d'avis" },
+                params: { expert_procedure: { id: expert_procedure.id }},
+                class: 'button' }
   - else
     .blank-tab
       %h2.empty-text Aucun expert invité pour le moment.
diff --git a/config/locales/views/new_administrateur/groupe_instructeurs/fr.yml b/config/locales/views/new_administrateur/groupe_instructeurs/fr.yml
index 6ac7df602..2243a9caf 100644
--- a/config/locales/views/new_administrateur/groupe_instructeurs/fr.yml
+++ b/config/locales/views/new_administrateur/groupe_instructeurs/fr.yml
@@ -1,5 +1,12 @@
 fr:
   new_administrateur:
+    experts_procedures:
+      wrong_address:
+          one: "%{value} n’est pas une adresse email valide"
+          other: "%{value} ne sont pas des adresses emails valides"
+      experts_assignment:
+          one: "L'expert %{value} a été affecté à la démarche n° %{procedure}"
+          other: "Les experts %{value} ont été affectés à la démarche n° %{procedure}"
     groupe_instructeurs:
       index:
         existing_groupe:
diff --git a/config/routes.rb b/config/routes.rb
index ab3874c57..81156cf26 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -408,7 +408,8 @@ Rails.application.routes.draw do
       post 'transfer' => 'procedures#transfer', as: :transfer
       get 'invited_expert_list'
       put 'update_allow_decision_access' => 'procedures#update_allow_decision_access', as: :update_allow_decision_access
-
+      post 'add_expert_to_procedure' => 'experts_procedures#add_expert_to_procedure', as: :add_expert_to_procedure
+      put 'revoke_expert_from_procedure' => 'experts_procedures#revoke_expert_from_procedure', as: :revoke_expert_from_procedure
       resources :mail_templates, only: [:edit, :update]
 
       resources :groupe_instructeurs, only: [:index, :show, :create, :update, :destroy] do
diff --git a/db/migrate/20210331184808_add_revoked_at_to_experts_procedures.rb b/db/migrate/20210331184808_add_revoked_at_to_experts_procedures.rb
new file mode 100644
index 000000000..916ac6b67
--- /dev/null
+++ b/db/migrate/20210331184808_add_revoked_at_to_experts_procedures.rb
@@ -0,0 +1,5 @@
+class AddRevokedAtToExpertsProcedures < ActiveRecord::Migration[6.1]
+  def change
+    add_column :experts_procedures, :revoked_at, :datetime
+  end
+end
diff --git a/db/migrate/20210402163003_exports_key_not_null.rb b/db/migrate/20210402163003_exports_key_not_null.rb
new file mode 100644
index 000000000..3de3d70fc
--- /dev/null
+++ b/db/migrate/20210402163003_exports_key_not_null.rb
@@ -0,0 +1,5 @@
+class ExportsKeyNotNull < ActiveRecord::Migration[6.1]
+  def change
+    change_column_null :exports, :key, false
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 6f2234ccb..ac440622d 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_03_31_123709) do
+ActiveRecord::Schema.define(version: 2021_04_02_163003) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -345,6 +345,7 @@ ActiveRecord::Schema.define(version: 2021_03_31_123709) do
     t.boolean "allow_decision_access", default: false, null: false
     t.datetime "created_at", precision: 6, null: false
     t.datetime "updated_at", precision: 6, null: false
+    t.datetime "revoked_at"
     t.index ["expert_id", "procedure_id"], name: "index_experts_procedures_on_expert_id_and_procedure_id", unique: true
     t.index ["expert_id"], name: "index_experts_procedures_on_expert_id"
     t.index ["procedure_id"], name: "index_experts_procedures_on_procedure_id"
@@ -354,7 +355,7 @@ ActiveRecord::Schema.define(version: 2021_03_31_123709) do
     t.string "format", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.text "key"
+    t.text "key", null: false
     t.index ["format", "key"], name: "index_exports_on_format_and_key", unique: true
   end
 
diff --git a/spec/controllers/experts/avis_controller_spec.rb b/spec/controllers/experts/avis_controller_spec.rb
index 3ce7d7e2d..af0b520dd 100644
--- a/spec/controllers/experts/avis_controller_spec.rb
+++ b/spec/controllers/experts/avis_controller_spec.rb
@@ -159,7 +159,7 @@ describe Experts::AvisController, type: :controller do
       let(:previous_avis_confidentiel) { false }
       let(:asked_confidentiel) { false }
       let(:intro) { 'introduction' }
-      let(:emails) { ["toto@totomail.com"] }
+      let(:emails) { "[\"toto@totomail.com\"]" }
       let(:invite_linked_dossiers) { nil }
 
       before do
@@ -176,7 +176,7 @@ describe Experts::AvisController, type: :controller do
 
     describe '#create_avis' do
       let!(:previous_avis) { create(:avis, dossier: dossier, claimant: claimant, experts_procedure: experts_procedure, confidentiel: previous_avis_confidentiel) }
-      let(:emails) { ['a@b.com'] }
+      let(:emails) { "[\"a@b.com\"]" }
       let(:intro) { 'introduction' }
       let(:created_avis) { Avis.last }
       let!(:old_avis_count) { Avis.count }
@@ -194,7 +194,7 @@ describe Experts::AvisController, type: :controller do
       context 'when an invalid email' do
         let(:previous_avis_confidentiel) { false }
         let(:asked_confidentiel) { false }
-        let(:emails) { ["toto.fr"] }
+        let(:emails) { "[\"toto.fr\"]" }
 
         it { expect(response).to render_template :instruction }
         it { expect(flash.alert).to eq(["toto.fr : Email n'est pas valide"]) }
@@ -205,7 +205,7 @@ describe Experts::AvisController, type: :controller do
       context 'ask review with attachment' do
         let(:previous_avis_confidentiel) { false }
         let(:asked_confidentiel) { false }
-        let(:emails) { ["toto@totomail.com"] }
+        let(:emails) { "[\"toto@totomail.com\"]" }
 
         it { expect(created_avis.introduction_file).to be_attached }
         it { expect(created_avis.introduction_file.filename).to eq("piece_justificative_0.pdf") }
@@ -216,7 +216,7 @@ describe Experts::AvisController, type: :controller do
       context 'with multiple emails' do
         let(:asked_confidentiel) { false }
         let(:previous_avis_confidentiel) { false }
-        let(:emails) { ["toto.fr,titi@titimail.com"] }
+        let(:emails) { "[\"toto.fr\",\"titi@titimail.com\"]" }
 
         it { expect(response).to render_template :instruction }
         it { expect(flash.alert).to eq(["toto.fr : Email n'est pas valide"]) }
diff --git a/spec/controllers/instructeurs/dossiers_controller_spec.rb b/spec/controllers/instructeurs/dossiers_controller_spec.rb
index 82b08ad2d..b31cb81c0 100644
--- a/spec/controllers/instructeurs/dossiers_controller_spec.rb
+++ b/spec/controllers/instructeurs/dossiers_controller_spec.rb
@@ -448,7 +448,7 @@ describe Instructeurs::DossiersController, type: :controller do
       }
     end
 
-    let(:emails) { ['email@a.com'] }
+    let(:emails) { "[\"email@a.com\"]" }
 
     context "notifications updates" do
       context 'when an instructeur follows the dossier' do
@@ -476,7 +476,7 @@ describe Instructeurs::DossiersController, type: :controller do
       it { expect(response).to redirect_to(avis_instructeur_dossier_path(dossier.procedure, dossier)) }
 
       context "with an invalid email" do
-        let(:emails) { ['emaila.com'] }
+        let(:emails) { "[\"emaila.com\"]" }
 
         before { subject }
 
@@ -487,7 +487,7 @@ describe Instructeurs::DossiersController, type: :controller do
       end
 
       context 'with multiple emails' do
-        let(:emails) { ["toto.fr,titi@titimail.com"] }
+        let(:emails) { "[\"toto.fr\",\"titi@titimail.com\"]" }
 
         before { subject }
 
diff --git a/spec/controllers/new_administrateur/experts_procedures_controller_spec.rb b/spec/controllers/new_administrateur/experts_procedures_controller_spec.rb
new file mode 100644
index 000000000..39e28e3f9
--- /dev/null
+++ b/spec/controllers/new_administrateur/experts_procedures_controller_spec.rb
@@ -0,0 +1,49 @@
+describe NewAdministrateur::ExpertsProceduresController, type: :controller do
+  let(:admin) { create(:administrateur) }
+
+  before do
+    sign_in(admin.user)
+  end
+  describe '#add_expert_to_procedure' do
+    let(:procedure) { create :procedure, administrateur: admin }
+    let(:expert) { create(:expert) }
+    let(:expert2) { create(:expert) }
+
+    subject do
+      post :add_expert_to_procedure,
+      params: { procedure_id: procedure.id, emails: "[\"#{expert.email}\",\"#{expert2.email}\"]" }
+    end
+
+    before do
+      subject
+    end
+
+    context 'of multiple experts' do
+      it { expect(procedure.experts.include?(expert)).to be_truthy }
+      it { expect(procedure.experts.include?(expert2)).to be_truthy }
+      it { expect(flash.notice).to be_present }
+      it { expect(response).to redirect_to(admin_procedure_invited_expert_list_path(procedure)) }
+    end
+  end
+
+  describe '#revoke_expert_from_procedure' do
+    let(:procedure) { create :procedure, administrateur: admin }
+    let(:expert) { create(:expert) }
+    let(:expert_procedure) { ExpertsProcedure.create(expert: expert, procedure: procedure) }
+
+    subject do
+      put :revoke_expert_from_procedure, params: { procedure_id: procedure.id, expert_procedure: { id: expert_procedure.id } }
+    end
+
+    before do
+      subject
+      expert_procedure.reload
+    end
+
+    context 'of multiple experts' do
+      it { expect(expert_procedure.revoked_at).to be_present }
+      it { expect(flash.notice).to be_present }
+      it { expect(response).to redirect_to(admin_procedure_invited_expert_list_path(procedure)) }
+    end
+  end
+end
diff --git a/spec/controllers/users/dossiers_controller_spec.rb b/spec/controllers/users/dossiers_controller_spec.rb
index 1bd747264..d69c83670 100644
--- a/spec/controllers/users/dossiers_controller_spec.rb
+++ b/spec/controllers/users/dossiers_controller_spec.rb
@@ -619,13 +619,14 @@ describe Users::DossiersController, type: :controller do
       it 'updates the champs' do
         subject
         expect(first_champ.reload.value).to eq('beautiful value')
-        expect(first_champ.dossier.reload.last_champ_updated_at).to eq(now)
         expect(piece_justificative_champ.reload.piece_justificative_file).to be_attached
       end
 
-      it 'updates the dossier modification date' do
+      it 'updates the dossier timestamps' do
         subject
-        expect(dossier.reload.updated_at.year).to eq(2100)
+        dossier.reload
+        expect(dossier.updated_at).to eq(now)
+        expect(dossier.last_champ_updated_at).to eq(now)
       end
 
       it 'updates the dossier state' do
@@ -635,22 +636,34 @@ describe Users::DossiersController, type: :controller do
 
       it { is_expected.to redirect_to(demande_dossier_path(dossier)) }
 
-      context 'when only files champs are modified' do
+      context 'when only a single file champ are modified' do
+        # A bug in ActiveRecord causes records changed through grand-parent <->  parent <-> child
+        # relationships do not touch the grand-parent record on change.
+        # This situation is hit when updating just the attachment of a champ (and not the
+        # champ itself).
+        #
+        # This test ensures that, whatever workaround we wrote for this, it still works properly.
+        #
+        # See https://github.com/rails/rails/issues/26726
         let(:submit_payload) do
           {
             id: dossier.id,
             dossier: {
-              champs_attributes: {
-                id: piece_justificative_champ.id,
-                piece_justificative_file: file
-              }
+              champs_attributes: [
+                {
+                  id: piece_justificative_champ.id,
+                  piece_justificative_file: file
+                }
+              ]
             }
           }
         end
 
-        it 'updates the dossier modification date' do
+        it 'updates the dossier timestamps' do
           subject
-          expect(dossier.reload.updated_at.year).to eq(2100)
+          dossier.reload
+          expect(dossier.updated_at).to eq(now)
+          expect(dossier.last_champ_updated_at).to eq(now)
         end
       end
     end
@@ -667,6 +680,12 @@ describe Users::DossiersController, type: :controller do
       it { expect(response).to render_template(:modifier) }
       it { expect(flash.alert).to eq(['nop']) }
 
+      it 'does not update the dossier timestamps' do
+        dossier.reload
+        expect(dossier.updated_at).not_to eq(now)
+        expect(dossier.last_champ_updated_at).not_to eq(now)
+      end
+
       it 'does not send an email' do
         expect(NotificationMailer).not_to receive(:send_initiated_notification)
 
diff --git a/spec/features/instructeurs/expert_spec.rb b/spec/features/instructeurs/expert_spec.rb
index ea2353d45..1529421ae 100644
--- a/spec/features/instructeurs/expert_spec.rb
+++ b/spec/features/instructeurs/expert_spec.rb
@@ -1,4 +1,4 @@
-feature 'Inviting an expert:' do
+feature 'Inviting an expert:', js: true do
   include ActiveJob::TestHelper
   include ActionView::Helpers
 
@@ -21,7 +21,7 @@ feature 'Inviting an expert:' do
       click_on 'Avis externes'
       expect(page).to have_current_path(avis_instructeur_dossier_path(procedure, dossier))
 
-      fill_in 'avis_emails', with: "#{expert.email}, #{expert2.email}"
+      page.execute_script("document.querySelector('#avis_emails').value = '[\"#{expert.email}\",\"#{expert2.email}\"]'")
       fill_in 'avis_introduction', with: 'Bonjour, merci de me donner votre avis sur ce dossier.'
       check 'avis_invite_linked_dossiers'
       page.select 'confidentiel', from: 'avis_confidentiel'
diff --git a/spec/features/instructeurs/instruction_spec.rb b/spec/features/instructeurs/instruction_spec.rb
index b1c5a794d..b0c9aeef6 100644
--- a/spec/features/instructeurs/instruction_spec.rb
+++ b/spec/features/instructeurs/instruction_spec.rb
@@ -1,4 +1,4 @@
-feature 'Instructing a dossier:' do
+feature 'Instructing a dossier:', js: true do
   include ActiveJob::TestHelper
 
   let(:password) { 'my-s3cure-p4ssword' }
@@ -101,11 +101,13 @@ feature 'Instructing a dossier:' do
     click_on 'Avis externes'
     expect(page).to have_current_path(avis_instructeur_dossier_path(procedure, dossier))
 
+    expert_email_formated = "[\"expert@tps.com\"]"
     expert_email = 'expert@tps.com'
-    ask_confidential_avis(expert_email, 'a good introduction')
+    ask_confidential_avis(expert_email_formated, 'a good introduction')
 
+    expert_email_formated = "[\"#{instructeur2.email}\"]"
     expert_email = instructeur2.email
-    ask_confidential_avis(expert_email, 'a good introduction')
+    ask_confidential_avis(expert_email_formated, 'a good introduction')
 
     click_on 'Personnes impliquées'
     expect(page).to have_text(expert_email)
@@ -206,7 +208,7 @@ feature 'Instructing a dossier:' do
   end
 
   def ask_confidential_avis(to, introduction)
-    fill_in 'avis_emails', with: to
+    page.execute_script("document.querySelector('#avis_emails').value = '#{to}'")
     fill_in 'avis_introduction', with: introduction
     select 'confidentiel', from: 'avis_confidentiel'
     click_on 'Demander un avis'