diff --git a/Gemfile b/Gemfile
index 988861a90..13763e699 100644
--- a/Gemfile
+++ b/Gemfile
@@ -79,7 +79,7 @@ gem 'zipline'
 gem 'zxcvbn-ruby', require: 'zxcvbn'
 
 group :test do
-  gem 'capybara' # Integration testing
+  gem 'capybara', '3.13.2' # Integration testing
   gem 'capybara-email' # Access emails during integration tests
   gem 'capybara-screenshot' # Save a dump of the page when an integration test fails
   gem 'capybara-selenium'
diff --git a/Gemfile.lock b/Gemfile.lock
index 41c577d6b..bbfe3c9ab 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -119,13 +119,13 @@ GEM
     browser (2.5.3)
     builder (3.2.3)
     byebug (10.0.2)
-    capybara (3.29.0)
+    capybara (3.13.2)
       addressable
       mini_mime (>= 0.1.3)
       nokogiri (~> 1.8)
       rack (>= 1.6.0)
       rack-test (>= 0.6.3)
-      regexp_parser (~> 1.5)
+      regexp_parser (~> 1.2)
       xpath (~> 3.2)
     capybara-email (3.0.1)
       capybara (>= 2.4, < 4.0)
@@ -722,7 +722,7 @@ DEPENDENCIES
   brakeman
   browser
   byebug
-  capybara
+  capybara (= 3.13.2)
   capybara-email
   capybara-screenshot
   capybara-selenium
diff --git a/app/controllers/instructeurs/procedures_controller.rb b/app/controllers/instructeurs/procedures_controller.rb
index a30a52f7e..3bd2f35e1 100644
--- a/app/controllers/instructeurs/procedures_controller.rb
+++ b/app/controllers/instructeurs/procedures_controller.rb
@@ -207,16 +207,19 @@ module Instructeurs
 
     def download_export
       export_format = params[:export_format]
-
+      notice_message = "Nous générons cet export. Lorsque celui-ci sera disponible, vous recevrez une notification par email accompagnée d'un lien de téléchargement."
       if procedure.should_generate_export?(export_format)
         procedure.queue_export(current_instructeur, export_format)
 
         respond_to do |format|
           format.js do
-            flash.notice = "Nous générons cet export. Lorsque celui-ci sera disponible, vous recevrez une notification par email accompagnée d'un lien de téléchargement."
+            flash.notice = notice_message
             @procedure = procedure
           end
         end
+      elsif procedure.export_queued?(export_format)
+        flash.notice = notice_message
+        redirect_to procedure
       else
         redirect_to url_for(procedure.export_file(export_format))
       end
diff --git a/app/javascript/components/TypesDeChampEditor/components/TypeDeChamp.js b/app/javascript/components/TypesDeChampEditor/components/TypeDeChamp.js
index b158d51da..5b4dc12fa 100644
--- a/app/javascript/components/TypesDeChampEditor/components/TypeDeChamp.js
+++ b/app/javascript/components/TypesDeChampEditor/components/TypeDeChamp.js
@@ -31,7 +31,7 @@ const TypeDeChamp = sortableElement(
       !isHeaderSection && !isExplication && !state.isAnnotation;
 
     const [ref, inView] = useInView({
-      threshold: [0.6]
+      threshold: 0.6
     });
 
     const updateHandlers = createUpdateHandlers(
diff --git a/app/javascript/shared/activestorage/ujs.js b/app/javascript/shared/activestorage/ujs.js
index 72d464b26..8efd98b86 100644
--- a/app/javascript/shared/activestorage/ujs.js
+++ b/app/javascript/shared/activestorage/ujs.js
@@ -1,4 +1,5 @@
 import ProgressBar from './progress-bar';
+import { fire } from '@utils';
 
 const INITIALIZE_EVENT = 'direct-upload:initialize';
 const START_EVENT = 'direct-upload:start';
@@ -36,8 +37,18 @@ addUploadEventListener(PROGRESS_EVENT, ({ detail: { id, progress } }) => {
   ProgressBar.progress(id, progress);
 });
 
-addUploadEventListener(ERROR_EVENT, ({ detail: { id, error } }) => {
-  ProgressBar.error(id, error);
+addUploadEventListener(ERROR_EVENT, event => {
+  // Display an error message
+  alert(
+    `Nous sommes désolés, une erreur s’est produite lors de l’envoi du fichier.
+
+    (${event.detail.error})`
+  );
+  // Prevent ActiveStorage from displaying its own error message
+  event.preventDefault();
+
+  ProgressBar.error(event.detail.id, event.detail.error);
+  fire(document, 'sentry:capture-exception', new Error(event.detail.error));
 });
 
 addUploadEventListener(END_EVENT, ({ detail: { id } }) => {
diff --git a/app/javascript/shared/track/sentry.js b/app/javascript/shared/track/sentry.js
index 23410535a..2db2fd708 100644
--- a/app/javascript/shared/track/sentry.js
+++ b/app/javascript/shared/track/sentry.js
@@ -10,4 +10,10 @@ if (enabled && key) {
     scope.setUser(user);
     scope.setExtra('browser', browser.modern ? 'modern' : 'legacy');
   });
+
+  // Register a way to explicitely capture messages from a different bundle.
+  addEventListener('sentry:capture-exception', event => {
+    const error = event.detail;
+    Sentry.captureException(error);
+  });
 }
diff --git a/app/jobs/cleanup_stale_exports_job.rb b/app/jobs/cleanup_stale_exports_job.rb
index f00346124..9344d4f14 100644
--- a/app/jobs/cleanup_stale_exports_job.rb
+++ b/app/jobs/cleanup_stale_exports_job.rb
@@ -2,9 +2,25 @@ class CleanupStaleExportsJob < ApplicationJob
   queue_as :cron
 
   def perform(*args)
-    ActiveStorage::Attachment.where(
+    attachments = ActiveStorage::Attachment.where(
       "name in ('csv_export_file', 'ods_export_file', 'xlsx_export_file') and created_at < ?",
       Procedure::MAX_DUREE_CONSERVATION_EXPORT.ago
-    ).find_each(&:purge_later)
+    )
+    attachments.each do |attachment|
+      procedure = Procedure.find(attachment.record_id)
+      # export can't be queued if it's already attached
+      #  so we clean the flag up just in case it was not removed during
+      # the asynchronous generation
+      case attachment.name
+      when 'csv_export_file'
+        procedure.update(csv_export_queued: false)
+      when 'ods_export_file'
+        procedure.update(ods_export_queued: false)
+      when 'xlsx_export_file'
+        procedure.update(xlsx_export_queued: false)
+      end
+      # and we remove the stale attachment
+      attachment.purge_later
+    end
   end
 end
diff --git a/app/models/procedure.rb b/app/models/procedure.rb
index d4703b465..6a6d3ecd6 100644
--- a/app/models/procedure.rb
+++ b/app/models/procedure.rb
@@ -145,6 +145,18 @@ class Procedure < ApplicationRecord
     !ods_export_file.attached? || ods_export_file.created_at < MAX_DUREE_CONSERVATION_EXPORT.ago
   end
 
+  def export_queued?(format)
+    case format.to_sym
+    when :csv
+      return csv_export_queued?
+    when :xlsx
+      return xlsx_export_queued?
+    when :ods
+      return ods_export_queued?
+    end
+    false
+  end
+
   def should_generate_export?(format)
     case format.to_sym
     when :csv
@@ -169,7 +181,6 @@ class Procedure < ApplicationRecord
   end
 
   def queue_export(instructeur, export_format)
-    ExportProcedureJob.perform_now(self, instructeur, export_format)
     case export_format.to_sym
     when :csv
       update(csv_export_queued: true)
@@ -178,6 +189,7 @@ class Procedure < ApplicationRecord
     when :ods
       update(ods_export_queued: true)
     end
+    ExportProcedureJob.perform_later(self, instructeur, export_format)
   end
 
   def prepare_export_download(format)
diff --git a/config/deploy.rb b/config/deploy.rb
index b8cfdd565..5e7b2062e 100644
--- a/config/deploy.rb
+++ b/config/deploy.rb
@@ -94,6 +94,8 @@ desc "Deploys the current version to the server."
 task :deploy do
   command 'export PATH=$PATH:/home/ds/.rbenv/bin:/home/ds/.rbenv/shims'
   command 'source /home/ds/.profile'
+  # increase db timeout to 5 minutes to allow long migration
+  command 'export PG_STATEMENT_TIMEOUT=300000'
 
   deploy do
     # Put things that will set up an empty directory into a fully set-up