Critical error by neve theme

Hello, one subpage is not available because of a critical error:
I cann see it has something to do with my neve theme, but I can not understand more than this..

Warning: Undefined array key "" in /mnt/web123/d3/38/58814338/htdocs/wp-content/themes/neve/header-footer-grid/Core/Builder/Abstract_Builder.php on line 1843 Fatal error: Uncaught Error: Call to a member function get_id() on null in /mnt/web123/d3/38/58814338/htdocs/wp-content/themes/neve/header-footer-grid/functions-template.php:95 Stack trace: #0 /mnt/web123/d3/38/58814338/htdocs/wp-content/themes/neve/header-footer-grid/templates/row-wrapper-mobile.php(24): HFG\component_setting() #1 /mnt/web123/d3/38/58814338/htdocs/wp-includes/template.php(772): require('...') #2 /mnt/web123/d3/38/58814338/htdocs/wp-content/themes/neve/header-footer-grid/Main.php(198): load_template() #3 /mnt/web123/d3/38/58814338/htdocs/wp-content/themes/neve/header-footer-grid/Core/Builder/Header.php(371): HFG\Main->load() #4 /mnt/web123/d3/38/58814338/htdocs/wp-content/themes/neve/header-footer-grid/Core/Builder/Abstract_Builder.php(1295):
and many more..

What does it say about my theme?