BROKEN with the WordPress 4.7 update

Same error – but I don’t have and never have had this plugin!
Usual procedure – turn all the plugins off, then back on to see which is interfering with some mysterious process!

I have the same problem with the fix from @garymarkfuller and Radgeek.
I went from PHP 5.6 tot PHP 7.1.
Worked fine till the 24th of februar and don’t know what changed.
The problem doesn’t occur on every RSS feed.
So my Dutch RSS feeds are well feed, but the English RSS does not feed at all all of a sudden. https://www.grtx.nl
Please, someone has suggestions?

• This reply was modified 7 years, 9 months ago by webitman. Reason: textual error

For now I blocked lines 297 and 298 in \wp-includes\class-wp-hook.php
// } elseif ( $the_[‘accepted_args’] >= $num_args ) {
// $value = call_user_func_array( $the_[‘function’], $args );
But this is not the solution.

I also got this:

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘wc_form_field_args’ not found or invalid function name in /home/mindssqc/site.com/wp-includes/class-wp-hook.php on line 298

anyone with answer how to fix this?

What is this error mean ???
Please help me, I try to clone my post but getting this error message.

“TypeError thrown
Argument 2 passed to WPSEO_Link_Watcher::save_post() must be an instance of WP_Post, null given, called in C:\xampp\htdocs\baliver\wp-includes\class-wp-hook.php on line 300”

plugins
All Meta Tags
By Arthur Gareginyan
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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

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Warning : class-wp-hook.php on line 298
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plugins
All Meta Tags
By Arthur Gareginyan
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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
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All Meta Tags, class-wp-hook
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i’m getting this error too. i believe it started after the recent security update.

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘_return_false’ not found or invalid function name in /wp-includes/class-wp-hook.php on line 298

i don’t have NextGEN Gallery installed on this site anymore though… it did use it once upon a time… Nor All Meta Tags.

the site seems to be functioning fine…