improve multiple submitters error message

app/controllers/start_form_controller.rb

@@ -25,7 +25,7 @@ class StartFormController < ApplicationController
       redirect_to start_form_completed_path(@template.slug, email: submitter_params[:email])
     else
       if filter_undefined_submitters(@template).size > 1 && @submitter.new_record?
-        @error_message = I18n.t('not_found')
+        @error_message = multiple_submitters_error_message
 
         return render :show
       end
@@ -117,4 +117,14 @@ class StartFormController < ApplicationController
 
     @template = Template.find_by!(slug:)
   end
+
+  # rubocop:disable Layout/LineLength
+  def multiple_submitters_error_message
+    if current_user&.account_id == @template.account_id
+      helpers.t('this_submission_has_multiple_signers_which_prevents_the_use_of_a_sharing_link_as_its_unclear_which_signer_is_responsible_for_specific_fields_to_resolve_this_follow_this_guide_to_define_the_default_signer_details_html')
+    else
+      I18n.t('not_found')
+    end
+  end
+  # rubocop:enable Layout/LineLength
 end

app/views/start_form/show.html.erb

@@ -30,7 +30,9 @@
         <div dir="auto" class="form-control !mt-0">
           <%= f.label :email, t('email'), class: 'label' %>
           <%= f.email_field :email, value: current_user&.email || params[:email] || @submitter.email, required: true, class: 'base-input', placeholder: t('provide_your_email_to_start') %>
-          <%= @error_message %>
+          <% if @error_message %>
+            <span class="label-text-alt text-red-400 mt-1"><%= @error_message %></span>
+          <% end %>
         </div>
         <toggle-submit dir="auto" class="form-control">
           <%= f.button button_title(title: t('start'), disabled_with: t('starting')), class: 'base-button' %>