diff --git a/app/controllers/recherche_controller.rb b/app/controllers/recherche_controller.rb
index 00626af60..f2d96ffb6 100644
--- a/app/controllers/recherche_controller.rb
+++ b/app/controllers/recherche_controller.rb
@@ -4,8 +4,7 @@ class RechercheController < ApplicationController
   PROJECTIONS = [
     { "table" => 'procedure', "column" => 'libelle' },
     { "table" => 'user', "column" => 'email' },
-    { "table" => 'procedure', "column" => 'procedure_id' },
-    { "table" => 'dossier', "column" => 'hidden_by_administration_at' }
+    { "table" => 'procedure', "column" => 'procedure_id' }
   ]
 
   def index
diff --git a/app/controllers/stats_controller.rb b/app/controllers/stats_controller.rb
index 1202df9c8..3032e67c7 100644
--- a/app/controllers/stats_controller.rb
+++ b/app/controllers/stats_controller.rb
@@ -31,7 +31,7 @@ class StatsController < ApplicationController
     @procedures_in_the_last_4_months = last_four_months_serie(procedures, :published_at)
 
     @dossiers_cumulative = stat.dossiers_cumulative
-    @dossiers_in_the_last_4_months = stat.dossiers_in_the_last_4_months
+    @dossiers_in_the_last_4_months = format_keys_as_months(stat.dossiers_in_the_last_4_months)
   end
 
   def download
@@ -136,11 +136,18 @@ class StatsController < ApplicationController
     end
   end
 
+  def format_keys_as_months(series)
+    series.transform_keys do |k|
+      date = k.is_a?(Date) ? k : (Date.parse(k) rescue k)
+      l(date, format: "%B %Y")
+    end
+  end
+
   def last_four_months_serie(association, date_attribute)
-    association
+    series = association
       .group_by_month(date_attribute, last: 4, current: super_admin_signed_in?)
       .count
-      .transform_keys { |date| l(date, format: "%B %Y") }
+    format_keys_as_months(series)
   end
 
   def cumulative_month_serie(association, date_attribute)
diff --git a/app/helpers/string_to_html_helper.rb b/app/helpers/string_to_html_helper.rb
index 8806863f6..8fc99684f 100644
--- a/app/helpers/string_to_html_helper.rb
+++ b/app/helpers/string_to_html_helper.rb
@@ -1,5 +1,6 @@
 module StringToHtmlHelper
   def string_to_html(str, wrapper_tag = 'p')
+    return nil if str.blank?
     html_formatted = simple_format(str, {}, { wrapper_tag: wrapper_tag })
     with_links = Anchored::Linker.auto_link(html_formatted, target: '_blank', rel: 'noopener')
     sanitize(with_links, attributes: ['target', 'rel', 'href'])
diff --git a/app/models/stat.rb b/app/models/stat.rb
index ce0109c5b..097c0c592 100644
--- a/app/models/stat.rb
+++ b/app/models/stat.rb
@@ -80,11 +80,7 @@ class Stat < ApplicationRecord
         association.group_by_month(date_attribute, last: 4, current: false).count
       end
 
-      month_serie(sum_hashes(*timeseries))
-    end
-
-    def month_serie(date_serie)
-      date_serie.keys.sort.each_with_object({}) { |date, h| h[I18n.l(date, format: "%B %Y")] = date_serie[date] }
+      sum_hashes(*timeseries).sort.to_h
     end
 
     def cumulative_month_serie(associations_with_date_attribute)
diff --git a/app/services/dossier_projection_service.rb b/app/services/dossier_projection_service.rb
index bb03493ba..52865c6ca 100644
--- a/app/services/dossier_projection_service.rb
+++ b/app/services/dossier_projection_service.rb
@@ -1,5 +1,5 @@
 class DossierProjectionService
-  class DossierProjection < Struct.new(:dossier_id, :state, :archived, :hidden_by_user_at, :columns)
+  class DossierProjection < Struct.new(:dossier_id, :state, :archived, :hidden_by_user_at, :hidden_by_administration_at, :columns)
   end
 
   TABLE = 'table'
@@ -21,8 +21,8 @@ class DossierProjectionService
     state_field = { TABLE => 'self', COLUMN => 'state' }
     archived_field = { TABLE => 'self', COLUMN => 'archived' }
     hidden_by_user_at_field = { TABLE => 'self', COLUMN => 'hidden_by_user_at' }
-
-    ([state_field, archived_field, hidden_by_user_at_field] + fields) # the view needs state and archived dossier attributes
+    hidden_by_administration_at_field = { TABLE => 'self', COLUMN => 'hidden_by_administration_at' }
+    ([state_field, archived_field, hidden_by_user_at_field, hidden_by_administration_at_field] + fields) # the view needs state and archived dossier attributes
       .each { |f| f[:id_value_h] = {} }
       .group_by { |f| f[TABLE] } # one query per table
       .each do |table, fields|
@@ -46,7 +46,7 @@ class DossierProjectionService
           .pluck(:id, *fields.map { |f| f[COLUMN].to_sym })
           .each do |id, *columns|
             fields.zip(columns).each do |field, value|
-              if [state_field, archived_field, hidden_by_user_at_field].include?(field)
+              if [state_field, archived_field, hidden_by_user_at_field, hidden_by_administration_at_field].include?(field)
                 field[:id_value_h][id] = value
               else
                 field[:id_value_h][id] = value&.strftime('%d/%m/%Y') # other fields are datetime
@@ -100,6 +100,7 @@ class DossierProjectionService
         state_field[:id_value_h][dossier_id],
         archived_field[:id_value_h][dossier_id],
         hidden_by_user_at_field[:id_value_h][dossier_id],
+        hidden_by_administration_at_field[:id_value_h][dossier_id],
         fields.map { |f| f[:id_value_h][dossier_id] }
       )
     end
diff --git a/app/views/instructeurs/dossiers/_header_actions.html.haml b/app/views/instructeurs/dossiers/_header_actions.html.haml
index 9bfb488fa..47f7b4893 100644
--- a/app/views/instructeurs/dossiers/_header_actions.html.haml
+++ b/app/views/instructeurs/dossiers/_header_actions.html.haml
@@ -28,8 +28,7 @@
             state: dossier.state,
             archived: dossier.archived,
             dossier_is_followed: current_instructeur&.follow?(dossier),
-            close_to_expiration: dossier.close_to_expiration?,
-            recently_deleted: dossier.hidden_by_administration? }
+            close_to_expiration: dossier.close_to_expiration? }
 
 
 .state-button
diff --git a/app/views/instructeurs/procedures/_dossier_actions.html.haml b/app/views/instructeurs/procedures/_dossier_actions.html.haml
index 49a142173..aab58893a 100644
--- a/app/views/instructeurs/procedures/_dossier_actions.html.haml
+++ b/app/views/instructeurs/procedures/_dossier_actions.html.haml
@@ -21,13 +21,7 @@
               %span.icon.archive
               .dropdown-description
                 Archiver le dossier
-        - if recently_deleted
-          %li.danger
-            = link_to restore_instructeur_dossier_path(procedure_id, dossier_id), method: :patch, data: { confirm: "Voulez vous vraiment restaurer le dossier #{dossier_id}" } do
-              %span.icon.reply
-              .dropdown-description
-                = t('views.instructeurs.dossiers.restore')
-        - else
+
           %li.danger
             = link_to supprimer_dossier_instructeur_dossier_path(procedure_id, dossier_id), method: :patch, data: { confirm: "Voulez vous vraiment supprimer le dossier #{dossier_id} ? Cette action est irréversible. \nNous vous suggérons de télécharger le dossier au format PDF au préalable." } do
               %span.icon.delete
diff --git a/app/views/instructeurs/procedures/show.html.haml b/app/views/instructeurs/procedures/show.html.haml
index edfda99b3..6734bd8de 100644
--- a/app/views/instructeurs/procedures/show.html.haml
+++ b/app/views/instructeurs/procedures/show.html.haml
@@ -132,14 +132,19 @@
               %td.status-col
                 %a.cell-link{ href: path }= status_badge(p.state)
 
-              %td.action-col.follow-col= render partial: 'dossier_actions',
-                  locals: { procedure_id: @procedure.id,
-                            dossier_id: p.dossier_id,
-                            state: p.state,
-                            archived: p.archived,
-                            dossier_is_followed: @followed_dossiers_id.include?(p.dossier_id),
-                            close_to_expiration: @statut == 'expirant',
-                            recently_deleted: @statut == 'supprimes_recemment' }
+              - if @statut == 'supprimes_recemment'
+                %td.action-col.follow-col
+                  = link_to restore_instructeur_dossier_path(@procedure, p.dossier_id), method: :patch, class: "button primary" do
+                    = t('views.instructeurs.dossiers.restore')
+
+              - else
+                %td.action-col.follow-col= render partial: 'dossier_actions',
+                    locals: { procedure_id: @procedure.id,
+                              dossier_id: p.dossier_id,
+                              state: p.state,
+                              archived: p.archived,
+                              dossier_is_followed: @followed_dossiers_id.include?(p.dossier_id),
+                              close_to_expiration: @statut == 'expirant' }
 
       = pagination
     - else
diff --git a/app/views/recherche/_hidden_dossier.html.haml b/app/views/recherche/_hidden_dossier.html.haml
new file mode 100644
index 000000000..7a5de7011
--- /dev/null
+++ b/app/views/recherche/_hidden_dossier.html.haml
@@ -0,0 +1,17 @@
+%td.folder-col
+  %p.cell-link
+    %span.icon.folder
+
+%td.number-col
+  %p.cell-link= p.dossier_id
+
+%td
+  %p.cell-link= procedure_libelle
+
+%td
+  %p.cell-link
+    = user_email
+    = "- #{t('views.instructeurs.dossiers.deleted_by_administration')}" if p.hidden_by_administration_at.present?
+
+%td.status-col
+  %p.cell-link= status_badge(p.state)
diff --git a/app/views/recherche/index.html.haml b/app/views/recherche/index.html.haml
index d84be0712..72c91916e 100644
--- a/app/views/recherche/index.html.haml
+++ b/app/views/recherche/index.html.haml
@@ -20,13 +20,14 @@
           %th.action-col.follow-col
       %tbody
         - @projected_dossiers.each do |p|
-          - procedure_libelle, user_email, procedure_id, hidden_by_administration = p.columns
+          - procedure_libelle, user_email, procedure_id = p.columns
           - instructeur_dossier =  @instructeur_dossiers_ids.include?(p.dossier_id)
           - expert_dossier = @dossier_avis_ids_h[p.dossier_id].present?
+          - hidden_by_administration = p.hidden_by_administration_at.present?
           - instructeur_and_expert_dossier = instructeur_dossier && expert_dossier
           - path = instructeur_dossier ? instructeur_dossier_path(procedure_id, p.dossier_id) : expert_avis_path(procedure_id, @dossier_avis_ids_h[p.dossier_id])
 
-          %tr
+          %tr{ class: [p.hidden_by_administration_at.present? && "file-hidden-by-user"] }
             - if instructeur_and_expert_dossier
               %td.folder-col.cell-link
                 %span.icon.folder
@@ -39,7 +40,11 @@
               %td.status-col
                 .cell-link= status_badge(p.state)
 
+            - elsif hidden_by_administration
+              = render partial: "recherche/hidden_dossier", locals: {p: p, procedure_libelle: procedure_libelle, user_email: user_email}
+
             - else
+
               %td.folder-col
                 %a.cell-link{ href: path }
                   %span.icon.folder
@@ -76,14 +81,19 @@
                             Donner mon avis
 
             - elsif instructeur_dossier
-              %td.action-col.follow-col= render partial: "instructeurs/procedures/dossier_actions",
+              - if hidden_by_administration
+                %td.action-col.follow-col
+                  = link_to restore_instructeur_dossier_path(procedure_id, p.dossier_id), method: :patch, class: "button primary" do
+                    = t('views.instructeurs.dossiers.restore')
+
+              - else
+                %td.action-col.follow-col= render partial: "instructeurs/procedures/dossier_actions",
                                                             locals: { procedure_id: procedure_id,
                                                                       dossier_id: p.dossier_id,
                                                                       state: p.state,
                                                                       archived: p.archived,
                                                                       dossier_is_followed: @followed_dossiers_id.include?(p.dossier_id),
-                                                                      close_to_expiration: nil,
-                                                                      recently_deleted: hidden_by_administration.blank? }
+                                                                      close_to_expiration: nil }
 
             - else
               %td
diff --git a/app/views/shared/attachment/_edit.html.haml b/app/views/shared/attachment/_edit.html.haml
index d61f555b9..124680296 100644
--- a/app/views/shared/attachment/_edit.html.haml
+++ b/app/views/shared/attachment/_edit.html.haml
@@ -29,6 +29,7 @@
       %p.attachment-error-title
         Une erreur s’est produite pendant l’envoi du fichier.
       %p.attachment-error-description
+        Une erreur inconnue s'est produite pendant l'envoi du fichier
     = button_tag type: 'button', class: 'button attachment-error-retry', data: { 'input-target': ".attachment-input-#{attachment_id}" } do
       %span.icon.retry
       Ré-essayer
diff --git a/app/views/shared/dossiers/_champ_row.html.haml b/app/views/shared/dossiers/_champ_row.html.haml
index 4392289d8..edb7f0788 100644
--- a/app/views/shared/dossiers/_champ_row.html.haml
+++ b/app/views/shared/dossiers/_champ_row.html.haml
@@ -57,7 +57,7 @@
             - when TypeDeChamp.type_champs.fetch(:number)
               = number_with_html_delimiter(c.to_s)
             - else
-              = format_text_value(c.to_s)
+              = format_text_value(c.to_s) unless c.blank?
 
       - if c.type_champ != TypeDeChamp.type_champs.fetch(:header_section)
         %td.updated-at
diff --git a/config/locales/en.yml b/config/locales/en.yml
index e6668fac8..4a482a470 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -140,7 +140,8 @@ en:
         archived_dossier: "This file will be kept for an additional month"
         delete_dossier: "Delete file"
         deleted_by_user: "File deleted by user"
-        restore: "Restore the file"
+        deleted_by_administration: "File deleted by administration"
+        restore: "Restore"
       avis:
         introduction_file_explaination: "File attached to the request for advice"
     users:
diff --git a/config/locales/fr.yml b/config/locales/fr.yml
index 4c230ae37..b66c9e56f 100644
--- a/config/locales/fr.yml
+++ b/config/locales/fr.yml
@@ -137,7 +137,8 @@ fr:
         archived_dossier: "Le dossier sera conservé 1 mois supplémentaire"
         delete_dossier: "Supprimer le dossier"
         deleted_by_user: "Dossier supprimé par l'usager"
-        restore: "Restaurer le dossier"
+        deleted_by_administration: "Dossier supprimé par l'administration"
+        restore: "Restaurer"
       avis:
         introduction_file_explaination: "Fichier joint à la demande d’avis"
     users:
diff --git a/spec/helpers/string_to_html_helper_spec.rb b/spec/helpers/string_to_html_helper_spec.rb
index 847b6def7..545bc0cbb 100644
--- a/spec/helpers/string_to_html_helper_spec.rb
+++ b/spec/helpers/string_to_html_helper_spec.rb
@@ -28,7 +28,7 @@ RSpec.describe StringToHtmlHelper, type: :helper do
     context "with empty decription" do
       let(:description) { nil }
 
-      it { is_expected.to eq('<p></p>') }
+      it { is_expected.to eq nil }
     end
 
     context "with a bad script" do
diff --git a/spec/models/stat_spec.rb b/spec/models/stat_spec.rb
index e9fc2edc2..41138d59a 100644
--- a/spec/models/stat_spec.rb
+++ b/spec/models/stat_spec.rb
@@ -57,24 +57,30 @@ describe Stat do
         create(:dossier, state: :en_construction, depose_at: i.months.ago)
         create(:deleted_dossier, dossier_id: i + 100, state: :en_construction, deleted_at: i.month.ago)
       end
-      rs = Stat.send(:cumulative_month_serie, [
-        [Dossier.state_not_brouillon, :depose_at],
-        [DeletedDossier.where.not(state: :brouillon), :deleted_at]
+      s = Stat.new({
+        dossiers_cumulative:
+                        Stat.send(:cumulative_month_serie, [
+                          [Dossier.state_not_brouillon, :depose_at],
+                          [DeletedDossier.where.not(state: :brouillon), :deleted_at]
+                        ])
+      })
+      s.save!
+      s.reload
+      # Use `Hash#to_a` to also test the key ordering
+      expect(s.dossiers_cumulative.to_a).to eq([
+        [formatted_n_months_ago(12), 2],
+        [formatted_n_months_ago(11), 4],
+        [formatted_n_months_ago(10), 6],
+        [formatted_n_months_ago(9), 8],
+        [formatted_n_months_ago(8), 10],
+        [formatted_n_months_ago(7), 12],
+        [formatted_n_months_ago(6), 14],
+        [formatted_n_months_ago(5), 16],
+        [formatted_n_months_ago(4), 18],
+        [formatted_n_months_ago(3), 20],
+        [formatted_n_months_ago(2), 22],
+        [formatted_n_months_ago(1), 24]
       ])
-      expect(rs).to eq({
-        12 => 2,
-        11 => 4,
-        10 => 6,
-        9 => 8,
-        8 => 10,
-        7 => 12,
-        6 => 14,
-        5 => 16,
-        4 => 18,
-        3 => 20,
-        2 => 22,
-        1 => 24
-      }.transform_keys { |i| i.months.ago.beginning_of_month.to_date })
     end
   end
 
@@ -85,16 +91,22 @@ describe Stat do
           create(:dossier, state: :en_construction, depose_at: i.months.ago)
           create(:deleted_dossier, dossier_id: i + 100, state: :en_construction, deleted_at: i.month.ago)
         end
-        rs = Stat.send(:last_four_months_serie, [
-          [Dossier.state_not_brouillon, :depose_at],
-          [DeletedDossier.where.not(state: :brouillon), :deleted_at]
-        ])
-        expect(rs).to eq({
-          "juillet 2021" => 2,
-          "août 2021" => 2,
-          "septembre 2021" => 2,
-          "octobre 2021" => 2
+        s = Stat.new({
+          dossiers_in_the_last_4_months:
+                                   Stat.send(:last_four_months_serie, [
+                                     [Dossier.state_not_brouillon, :depose_at],
+                                     [DeletedDossier.where.not(state: :brouillon), :deleted_at]
+                                   ])
         })
+        s.save!
+        s.reload
+        # Use `Hash#to_a` to also test the key ordering
+        expect(s.dossiers_in_the_last_4_months.to_a).to eq([
+          ['2021-07-01', 2],
+          ['2021-08-01', 2],
+          ['2021-09-01', 2],
+          ['2021-10-01', 2]
+        ])
       end
     end
   end
@@ -104,4 +116,8 @@ describe Stat do
       expect(Stat.send(:sum_hashes, *[{ a: 1, b: 2, d: 5 }, { a: 2, b: 3, c: 5 }])).to eq({ a: 3, b: 5, c: 5, d: 5 })
     end
   end
+
+  def formatted_n_months_ago(i)
+    i.months.ago.beginning_of_month.to_date.to_s
+  end
 end