Wordpress error: no log, no message, no info

0
votes

I have upgraded a not so old version of a Wordpress site and also upgraded the server from php 5.6 to php 7.2 (all this in a local and controlled environment).

The site has a few plugins and a custom theme. Plugins where disabled and re-enabled one by one to control errors.

After the upgrade of all plugins that allowed an upgrade I've been tracking errors and solving them until this point where I am, where:

When entering theme options and another plugin configuration I get the error message:

The site is experiencing technical difficulties. Please check your email for instructions.

I don't find any error trace in apache/php error log and in Wordpress debug log. All PHP configuration is set up to show all errors and my wp-config.php file has these lines to force debug and log:

define('WP_DEBUG', true );
define('WP_DEBUG_LOG', true );
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

Where can I get more specific information about these errors? I know which plugins/theme cause them, but I need to debug and locate the lines where they happen.

Thank you.

2
phpwordpresslogging
Are you by any chance using betheme? or you have revslider? or jscomposer? – Masivuye Cokile
Yes to revslider and yes to jscomposer, jscomposer can show and render previous pages but is unable to edit them. Revslider seems to be working properly. – K. Weber
The problem is jscomposer.... I will check now for you which line I experienced this a lot.... try and set error reporting of your server on – Masivuye Cokile
Uncaught Error: [] operator not supported for strings in ../wp-content/plugins/revslider/includes/framework/base-admin.class.php:71 can you check your revslider for line 71 – Masivuye Cokile
But if I disable both plugins I have the same error, so my problem is different than yours. I need a way to find log for the real error. Thank you. – K. Weber

2 Answers

0
votes

Please follow the below steps:

  1. Paste these below code in wp-config.php

    define( 'WP_DEBUG', true );

    define( 'WP_DEBUG_LOG', true );

    define( 'WP_DEBUG_DISPLAY', true );

    @ini_set( 'display_errors', 1 );

    define( 'SCRIPT_DEBUG', true );

  2. create a file named debug.log in the wp-content directory.

3.Run your WordPress website like before and open debug.log file in any text editor. You will find all the everything (erros) here.

0
votes

So, I found the script where Wordpress handles fatal errors, and where it masks these errors under the generic message:

The site is experiencing technical difficulties. Please check your email for instructions.

The script /wp-includes/class-wp-fatal-error-handler.php handles these errors, under a try..catch block, which makes it impossible to the error message to show up.

So, a temporal solution, only for debugging, is to modify the method handle() to disable the try..catchand log the error message, like shown here:

disclaimer: this modification must be undone once the site is put into production, it's only for debugging purposes.

public function handle() {
        if ( defined( 'WP_SANDBOX_SCRAPING' ) && WP_SANDBOX_SCRAPING ) {
            return;
        }
        // comment try..catch
        // try {
            // Bail if no error found.
            $error = $this->detect_error();
            if ( ! $error ) {
                return;
            }

//log error message
error_log($error["message"]);
return;

            if ( ! isset( $GLOBALS['wp_locale'] ) && function_exists( 'load_default_textdomain' ) ) {
                load_default_textdomain();
            }

            if ( ! is_multisite() && wp_recovery_mode()->is_initialized() ) {
                wp_recovery_mode()->handle_error( $error );
            }

            // Display the PHP error template if headers not sent.
            if ( is_admin() || ! headers_sent() ) {
                $this->display_error_template( $error );
            }
        // } catch ( Exception $e ) {
            // Catch exceptions and remain silent.
        // }
    }

The function error_log will log error to wp-content/debug.log in the case that this line exists in your wp-config.php file:

define( 'WP_DEBUG_LOG', true );

Or to Apache/php error log otherwise.

Sure there are other ways and other configurations to debug these errors but this is an easy one.