Quit working when I updated to WP 5.9

By “cannot edit the code” do you mean that you cannot open the “WP Admin -> Custom CSS & JS” page, or that you cannot open an any of the individual custom codes?

What PHP version do you have on the server?

Would you make sure the debugging mode is enabled on your website, as per this article? An error message would really be helpful.

I should mention it is still placing the code that I have added, I just cannot edit it.

Ok, that is useful information, but it doesn’t answer any of my questions.

The server is running PHP 8.1.2
DB is MariaDB 10.3

Will enable debug and see if I can get a msg

I cannot edit the individual items. Sent an email but it is not showing here.

The error should be at the end of the email, in the “Error Details” section.

That is the thing, I am not getting the email. I checked the email address and I do get other emails from the server but not the error email it indicates.

After enabling the debugging mode, do you get an error in the debug log?

Also the Apache logs should hold any PHP errors generated on the website. Can you open the server logs?

Okay, here is what is in the debug log

[28-Jan-2022 21:21:00 UTC] PHP Fatal error:  Uncaught Exception: Serialization of 'Closure' is not allowed in /home/mydomain/public_html/wp-includes/functions.php:617
Stack trace:
#0 /home/mydomain/public_html/wp-includes/functions.php(617): serialize(Array)
#1 /home/mydomain/public_html/wp-includes/option.php(458): maybe_serialize(Array)
#2 /home/mydomain/public_html/wp-content/plugins/user-rights-access-manager/admin/admin_menu_handle.php(18): update_option('wp_meta_boxes_d...', Array)
#3 /home/mydomain/public_html/wp-includes/class-wp-hook.php(309): wpres_admin_menu_handle->wpres_get_metabox_value('custom-css-js')
#4 /home/mydomain/public_html/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters(NULL, Array)
#5 /home/mydomain/public_html/wp-includes/plugin.php(474): WP_Hook->do_action(Array)
#6 /home/mydomain/public_html/wp-admin/includes/meta-boxes.php(1581): do_action('add_meta_boxes', 'custom-css-js', Object(WP_Post))
#7 /home/mydomain/public_html/wp-admin/edit-form-advanced.php(271): register_and_do_post_meta_boxe in /home/mydomain/public_html/wp-includes/functions.php on line 617

Would you deactivate the User Rights Access Manager plugin for a moment and see if the error is still there?

Here is another support topic with the exact same error message: I cannot edit post with plugin.

That is it. Has been in place for a while with no issues but when I deactivate it all is good. Sorry to bother you with an issue that was not yours. Thanks for your help.

You’re welcome.

Bought the developer PRO edition due to awesome support.