diff --git a/app/controllers/new_gestionnaire/procedures_controller.rb b/app/controllers/new_gestionnaire/procedures_controller.rb
index 71ba18093..4c8ac5d56 100644
--- a/app/controllers/new_gestionnaire/procedures_controller.rb
+++ b/app/controllers/new_gestionnaire/procedures_controller.rb
@@ -212,7 +212,11 @@ module NewGestionnaire
     end
 
     def get_procedure_presentation
-      current_gestionnaire.procedure_presentation_for_procedure_id(params[:procedure_id])
+      procedure_presentation, errors = current_gestionnaire.procedure_presentation_and_errors_for_procedure_id(params[:procedure_id])
+      if errors.present?
+        flash[:alert] = "Votre affichage a dû être réinitialisé en raison du problème suivant : " + errors.full_messages.join(', ')
+      end
+      procedure_presentation
     end
 
     def displayed_fields_values
diff --git a/app/models/assign_to.rb b/app/models/assign_to.rb
index af232d267..1e21528b4 100644
--- a/app/models/assign_to.rb
+++ b/app/models/assign_to.rb
@@ -3,7 +3,7 @@ class AssignTo < ApplicationRecord
   belongs_to :gestionnaire
   has_one :procedure_presentation, dependent: :destroy
 
-  def procedure_presentation_or_default
-    procedure_presentation || build_procedure_presentation
+  def procedure_presentation_or_default_and_errors
+    [procedure_presentation || build_procedure_presentation, nil]
   end
 end
diff --git a/app/models/gestionnaire.rb b/app/models/gestionnaire.rb
index 675cafebb..ae9030646 100644
--- a/app/models/gestionnaire.rb
+++ b/app/models/gestionnaire.rb
@@ -81,8 +81,8 @@ class Gestionnaire < ApplicationRecord
     end
   end
 
-  def procedure_presentation_for_procedure_id(procedure_id)
-    assign_to.find_by(procedure_id: procedure_id).procedure_presentation_or_default
+  def procedure_presentation_and_errors_for_procedure_id(procedure_id)
+    assign_to.find_by(procedure_id: procedure_id).procedure_presentation_or_default_and_errors
   end
 
   def notifications_for_dossier(dossier)
diff --git a/spec/models/assign_to_spec.rb b/spec/models/assign_to_spec.rb
index 9b520c188..fbd3e59d0 100644
--- a/spec/models/assign_to_spec.rb
+++ b/spec/models/assign_to_spec.rb
@@ -1,18 +1,22 @@
 describe AssignTo, type: :model do
-  describe '#procedure_presentation_or_default' do
+  describe '#procedure_presentation_or_default_and_errors' do
     let(:procedure) { create(:procedure) }
     let(:assign_to) { AssignTo.create(procedure: procedure) }
 
-    let(:procedure_presentation_or_default) { assign_to.procedure_presentation_or_default }
+    let(:procedure_presentation_and_errors) { assign_to.procedure_presentation_or_default_and_errors }
+    let(:procedure_presentation_or_default) { procedure_presentation_and_errors.first }
+    let(:errors) { procedure_presentation_and_errors.second }
 
     context "without a procedure_presentation" do
       it { expect(procedure_presentation_or_default).not_to be_persisted }
+      it { expect(errors).to be_nil }
     end
 
     context "with a procedure_presentation" do
       let!(:procedure_presentation) { ProcedurePresentation.create(assign_to: assign_to) }
 
       it { expect(procedure_presentation_or_default).to eq(procedure_presentation) }
+      it { expect(errors).to be_nil }
     end
   end
 end
diff --git a/spec/models/gestionnaire_spec.rb b/spec/models/gestionnaire_spec.rb
index fc9ab72bc..df119bc25 100644
--- a/spec/models/gestionnaire_spec.rb
+++ b/spec/models/gestionnaire_spec.rb
@@ -197,20 +197,24 @@ describe Gestionnaire, type: :model do
     end
   end
 
-  describe "procedure_presentation_for_procedure_id" do
-    let(:procedure_presentation) { gestionnaire.procedure_presentation_for_procedure_id(procedure_id) }
+  describe "procedure_presentation_and_errors_for_procedure_id" do
+    let(:procedure_presentation_and_errors) { gestionnaire.procedure_presentation_and_errors_for_procedure_id(procedure_id) }
+    let(:procedure_presentation) { procedure_presentation_and_errors.first }
+    let(:errors) { procedure_presentation_and_errors.second }
 
     context 'with explicit presentation' do
       let(:procedure_id) { procedure.id }
       let!(:pp) { ProcedurePresentation.create(assign_to: procedure_assign) }
 
       it { expect(procedure_presentation).to eq(pp) }
+      it { expect(errors).to be_nil }
     end
 
     context 'with default presentation' do
       let(:procedure_id) { procedure_2.id }
 
       it { expect(procedure_presentation).not_to be_persisted }
+      it { expect(errors).to be_nil }
     end
   end