Warning after upgrading to 4.7

Try deactivating all plugins. If that resolves the issue, reactivate each one individually until you find the cause.

If that does not resolve the issue, try switching to the Twenty Seventeen theme to rule-out a theme-specific issue (theme functions can interfere like plugins).

I have the exact same issue. I deactivated all plugins and it’s still there. Only if I chose the standard theme, then the warning goes away.

Ok, then you’ll need to contact the developer of your theme about this.

I found out it was an old plugin: WP LocalScroll, deactivating removed the error

If the theme author is no longer around, how can I find out which component is causing the warning – is there a debugging button somewhere? I’ve used something like this on other CMSs…

Hi brembs! I assume, from going to your profile site, that you resolved your problem. Wonder if you could point me in the correct direction. After trying to upgrade to Vaughan 4.7, I get error messages in Admin — so I don’t even know how to undo (I did backup database; not the whole site). I see two error messages that seem like they are similar to what you reported:

Warning: call_user_func_array() expects parameter 1 to be a valid callback, no array or string given in /home/xxxxxx/public_html/app/wp-includes/class-wp-hook.php on line 298

Warning: Cannot modify header information – headers already sent by (output started at /home/xxxxxx/public_html/app/wp-includes/class-wp-hook.php:298) in /home/xxxxxx/public_html/app/wp-includes/pluggable.php on line 1179

I feel presumptuous asking for your help … thank you! … in a panic, esp. since I cannot even get into admin view.

Kevin

Don’t know if you still need help with this. I got the same error. Turns out (at least for me) the ORDER of the updates makes a difference. When I updated to 4.7.1 BEFORE updating my theme and the plugins, I got the error message you’re describing above. My site was broken, so I first had to restore my site with the FORMER version of WordPress (in my case, 4.5). Then I first updated the theme. Then the plug-ins. Then WordPress. Now everything’s copacetic!

– Julie

I have the same problem with a 4.8 upgrade of WP. I first did that, and after, download the Enfold upgrading files, get from 3.7.1 ti 4.0.7.
But i had a lot of dysfonctions, with Layer Slider (one doesn’t work) and GF.
My debug log was full issues of :
undefined index;
call_user_func_array() ; wp_register_style was called incorrectly;
Non-static method…
essentially.
Reading your posts i guess that most of my problems came from my upgrade. Do you think i have to retrograde my WP, then upgrading Enfold and plugins?
Enfold say that its theme is compatible with 4.7… not 4.8. What is your advice?

.
Warning : class-wp-hook.php on line 298
.
plugins
All Meta Tags
By Arthur Gareginyan
.
Warning: call_user_func_array() expects parameter 1 to be a valid callback, no array or string given in /home/www/web411/html/bjoern/wp/wp-includes/class-wp-hook.php on line 298
.
plugins
All Meta Tags
By Arthur Gareginyan
.
Warning: call_user_func_array() expects parameter 1 to be a valid callback, no array or string given in /home/www/web411/html/bjoern/wp/wp-includes/class-wp-hook.php on line 298
.
All Meta Tags, class-wp-hook
.