E_ERROR was caused in line 292 of the file in event ticket plus how to fix this

Uncaught Error: Call to a member function add_qty() on null in /plugins/event-tickets-plus/src/Tribe/Commerce/EDD/Orders/Report.php:292

Uncaught Error: Call to a member function add_qty() on null in 
/plugins/event-tickets-plus/src/Tribe/Commerce/EDD/Orders/Report.php:292
Stack trace:
#0 /WordPress/wp-includes/class-wp-hook.PHP(307): Tribe_Tickets_PlusCommerceEDDOrders_Report->orders_page_inside('')
#1 /wordpress/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters('', Array)
#2 /wordpress/wp-includes/plugin.php(476): WP_Hook->do_action(Array)
#3 /wordpress/wp-admin/admin.php(259): do_action('tribe_events_pa...')
#4 /wordpress/wp-admin/edit.php(10): require_once('/wordpress/wp-a...')
#5 {main}
  thrown