Critical error in Wordpress navigation menu with PHP 8

SLH3 commented 6 months ago

Hi there… I have the following installation:

Wordpress 6.4.3
PHP 8.1.27
Gantry 5.5.17
Theme: Helium 5.5.17 Since the change of PHP 7.4 to PHP 8.1, I have a problem opening the Wordpress navigation menu:

The following critical error appears, but is only visible in the backend:

I checked the following:

Disable various plugins: The error is still persistent
Downgrade to PHP7.4: Wordpress navigation menu works fine. The PHP-version 8.0, 8.1, 8.2 and 8.3 leads to the critical error.
Wordpress Query monitor: Doesn’t show an error or a warning for Gantry framework plugin.
Using the gantry menu editor works fine. But I’m working with the Wordpress menu editor since I have to add blog categories as a menu item.

The frontend works fine. I guess, it’s a Gantry PHP8 compatibility error but I have no idea what it could be😉.

Many thanks and best regards, David

SLH3 commented 5 months ago

Is there anybody else with the same (WordPress) error?

jazzmang commented 5 months ago

Is there anybody else with the same (WordPress) error?

It is working fine on PHP 8.1 on a site we are currently in development.

One thing I can say is that the WP Form and WP SMTP plug-ins in WP do cause issues when working with Gantry, although I don't think the menu was one of them (it was edited under the framework). So my guess is you have a plugin causing an issue. You might try disabling them one by one.

hexplor commented 5 months ago

Can you please show me the list of plugins? I'd love to check what's causing the error...

SLH3 commented 5 months ago

Hi there Sorry for the late reply... I was out of office.

The error was caused by a plugin-in called "Recent Post to WP Nav Menu", which is deprecated for a long time. Curiously, the plugin wasn't displayed in the plugin list and I didn't deactivate it 3 weeks ago. I found it, by going through the error message step by step (as I should have done it in the first place). After "installing" it again and removing it, everything works!:-)

I would like to thank everybody for their time and efforts! And I'm very sorry I didn't find it in the first place.

coffiCwtch commented 1 month ago

I am having this same issue, however it tracking to admin/init.php, lines 84-95.

gantry / gantry5

Critical error in Wordpress navigation menu with PHP 8 #3237