Attempt to assign property on null

Today I migrated a WordPress installation from one shared webhost to a new one.

At first glance everyting seems just fine. But…

Problem:
When trying to create a new post or page, the following errors occur:

Warning: Attempt to read property "post_type" on null in /www/wp/wp-includes/post.php on line 7502

Warning: Attempt to read property "post_type" on null in /www/wp/wp-includes/post.php on line 7503

Warning: Attempt to read property "ID" on null in /www/wp/wp-includes/post.php on line 7507

Warning: Attempt to read property "post_type" on null in /www/wp/wp-includes/post.php on line 7762

Warning: Attempt to read property "post_type" on null in /www/wp/wp-includes/theme.php on line 3596

Warning: Attempt to read property "post_type" on null in /www/wp/wp-includes/theme.php on line 3822

Warning: Attempt to read property "post_type" on null in /www/wp/wp-includes/post.php on line 5448

Warning: Attempt to read property "ID" on null in /www/wp/wp-includes/post.php on line 5448

Warning: Attempt to read property "post_type" on null in /www/wp/wp-includes/post.php on line 4749

Fatal error: Uncaught Error: Attempt to assign property "post_content" on null in /www/wp/wp-admin/includes/post.php:795 Stack trace: #0 /www/wp/wp-admin/post-new.php(66): get_default_post_to_edit('page', true) #1 {main} thrown in /www/wp/wp-admin/includes/post.php on line 795

Migration steps:
1) Backup FTP
2) Backup SQL (PHPmyAdmin)
3) Update core + plugins + themes
4) 2nd Backup FTP
5) 2nd Backup SQL (PHPmyAdmin)
6) Upload 2nd backup to new shared host
7) Change DNS records
8) Wait and test

Troubleshooting steps without success:

• Disable all plugins manually
• Switch to Twenty Twenty-Four theme
• Using “Troubleshooting Mode” via https://www.ads-software.com/plugins/health-check/
• Drop all tables in DB and importing SQL again without “Do not use AUTO_INCREMENT for zero values” checked

Might be?
The only real difference I can spot is that the new host is running on PHP v8.2 and the old host was running om PHP v7.4

The new host only allows PHP 8.1 + 8.2 + 8.3, and I have tried them all without luck.

So now:
I could use some help please…

WordPress Version 6.4.3

• This topic was modified 9 months, 2 weeks ago by l1512191.