Show error messages

There shouldn't normally be errors, but I got one due to bad data during development, and this helped sort it out.

app/controllers/admin/column_preferences_controller.rb

@@ -18,7 +18,7 @@ module Admin
         respond_to do |format|
           format.json { render json: { errors: @cp_set.errors }, status: :bad_request }
           format.turbo_stream {
-            flash.now[:error] = t('.error')
+            flash.now[:error] = @cp_set.errors.full_messages.to_sentence
             render :bulk_update, locals: { action: permitted_params[:action_name] }
           }
         end
@@ -55,6 +55,7 @@ module Admin
           }
         end
       end
+
       @cp_set = Sets::ColumnPreferenceSet.new(@column_preferences, collection_attributes:)
     end
 

config/locales/en.yml

@@ -764,7 +764,6 @@ en:
     column_preferences:
       bulk_update:
         success: "Column preferences saved"
-        error: "Column preferences could not be saved"
     contents:
       edit:
         title: Content