Fixes postgres issue

app/controllers/projects_controller.rb

@@ -327,6 +327,8 @@ private
   end
 
   def types_used_by_work_packages
-    @types_used_by_work_packages ||= Type.find_all_by_id(@project.work_packages.select(:type_id).uniq)
+    @types_used_by_work_packages ||= Type.find_all_by_id(WorkPackage.where(project_id: @project.id)
+                                                                    .select(:type_id)
+                                                                    .uniq)
   end
 end