I have display suite and field group installed on drupal 7, when I click the cog icon, i getting error with message like this :An Ajax HTTP error occured.HTTP Result Code: 200 Debugging information follows.Path : system/ajaxStatus Text : OKResponeText :Fatal error : Unsupported operand types in : ..... common.inc on line 6697After that, I try to check the one that made error as described in the