Notice: Trying to get property of non-object in nav-menu.php on line 665

Hi,
Had problem with creating new pages,kept grabbing old permalinks.
Deleted page causing prob now getting message on home page screen>
Trying to get property of non-object in nav-menu.php on line 665
checked nav_menu.php file all looks ok! anyone come across this or can help

help is apreciated
Cheers

https://www.ads-software.com/plugins/menu/