Getting 2 Backend WordPress Errors after Updating Theme & Cornerstone

[langleydesigngroup]

The front end of the website looks fine, but I keep getting this error on the backend after updating Cornerstone and installing a fresh version of X. Can you help?

Warning: call_user_func_array() expects parameter 1 to be a valid callback, array must have exactly two members in /home/customer/www/willl21.sg-host.com/public_html/wp-includes/class-wp-hook.php on line 309

Warning: Cannot modify header information - headers already sent by (output started at /home/customer/www/willl21.sg-host.com/public_html/wp-includes/class-wp-hook.php:309) in /home/customer/www/willl21.sg-host.com/public_html/wp-admin/admin-header.php on line 9

This is on a staging site at the moment, which is why the domain looks weird.

[ruenel]

Hello @langleydesigngroup,

Thanks for writing in! What you are seeing is not an error. It is a PHP Warning that appears because your WP debug mode is enabled. Disable the debug mode to get rid of the PHP Warnings.

Those warning by the way may have come from your server settings. Check your PHP version. You must have at least PHP 7.4. For complete server settings and plugin compatibility, please check this out:

• Version Compatibility (theme.co)

It may also have come from 3rd party plugin conflict amongst other things. Please do the following as well:

• Testing For Theme Related Issue
• Testing For Plugin Conflict
• Theme Update
• Child Theme
• Increasing Php Memory Limit
• Disabling Cache
• Disabling Cdn
• Permalinks
• Version Compatibility

If you are still having difficulties, we would love to check your site. You can create a secure note in your next reply with the following info:
– Link to your site
– WP login URL
– WP username
– WP password
– WP Administrator Role
- Confirmation that we can access and make changes to your site
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To know how to create a secure note, please check this out: How The Forum Works

Best Regards.

[langleydesigngroup]

Thank you for your quick response! I checked and made sure that the Debug mode was off/false… it was… but then found that there was a plugin causing it as I deactivated them one by one. I’ll keep this in mind before reaching out for silly help again!

[ruenel]

You are most welcome, @langleydesigngroup.