warning attempt to read property "id" on null in...

[PB22]

I have four warnings appearing on the top of the website:

Warning: Attempt to read property "post_name" on null in /homepages/19/d919426286/htdocs/clickandbuilds/SummerSchool22/wp-content/themes/lay/frontend/frontend.php on line 90
Warning: Attempt to read property "ID" on null in /homepages/19/d919426286/htdocs/clickandbuilds/SummerSchool22/wp-content/themes/lay/frontend/assets/php/layout.php on line 139
Warning: Attempt to read property "post_name" on null in /homepages/19/d919426286/htdocs/clickandbuilds/SummerSchool22/wp-content/themes/lay/frontend/assets/php/layout.php on line 140
Warning: Attempt to read property "ID" on null in /homepages/19/d919426286/htdocs/clickandbuilds/SummerSchool22/wp-content/themes/lay/frontend/assets/php/layout.php on line 142

what can I do to fix it?

[arminunruh]

set the frontpage in customizer -> frontpage

[PB22]

@arminunruh

thank you, that was too easy.