title: error message "www/wp-includes/l10n.php on line 69" since last wordpress update 5.5.3
body: <p>Since the last update of wordpress 5.5.3, i've a 505 error. from the debug mode, i've this error.</p>
  <p>configuration:</p>
  <ul>
  <li>wordpress 5.5.3</li>
  <li>divi theme</li>
  <li>OVH server provider</li>
  <li>PHP 7.2</li>
  </ul>
  <blockquote>
  <p>Fatal error: Uncaught Error: Call to undefined function get_option()
  in /home/website/www/wp-includes/l10n.php:69 Stack trace: #0
  /home/website/www/wp-includes/l10n.php(137): get_locale() #1
  /home/website/www/wp-includes/l10n.php(828): determine_locale() #2
  /home/website/www/wp-includes/class-wp-fatal-error-handler.php(41):
  load_default_textdomain() #3 [internal function]:
  WP_Fatal_Error_Handler-&gt;handle() #4 {main} thrown in
  /home/lecatamakp/www/wp-includes/l10n.php on line 69</p>
  </blockquote>
  <p>some solutions, i did but don't work.</p>
  <ul>
  <li>restore a backup from 5 days.</li>
  <li>disable <code>plugins</code> folder</li>
  <li>disable <code>theme</code> folder</li>
  <li>raise the the php_memory limit to 256MB</li>
  <li>change the PHP version</li>
  <li>compare an old backup (15days) with the actual app with <code>diff -rq backup actual_app </code> and i have not difference. there are absolutely the same.</li>
  </ul>
  <p>the problem come from <code>l10n.php</code></p>
  <pre><code>unction get_locale() {
  global $locale, $wp_local_package;
  
  if ( isset( $locale ) ) {
      /**
       * Filters the locale ID of the WordPress installation.
       *
       * @since 1.5.0
       *
       * @param string $locale The locale ID.
       */
      return apply_filters( 'locale', $locale );
  }
  
  if ( isset( $wp_local_package ) ) {
      $locale = $wp_local_package;
  }
  
  // WPLANG was defined in wp-config.
  if ( defined( 'WPLANG' ) ) {
      $locale = WPLANG;
  }
  
  // If multisite, check options.
  if ( is_multisite() ) {
      // Don't check blog option when installing.
      if ( wp_installing() ) {
          $ms_locale = get_site_option( 'WPLANG' );
      } else {
          $ms_locale = get_option( 'WPLANG' );
          if ( false === $ms_locale ) {
              $ms_locale = get_site_option( 'WPLANG' );
          }
      }
  
      if ( false !== $ms_locale ) {
          $locale = $ms_locale;
      }
  } else {
      $db_locale = get_option( 'WPLANG' ); #--------------HERE IS THE PROBLEM----------------
      if ( false !== $db_locale ) {
          $locale = $db_locale;
      }
  }
  
  if ( empty( $locale ) ) {
      $locale = 'en_US';
  }
  
  /** This filter is documented in wp-includes/l10n.php */
  return apply_filters( 'locale', $locale );
  </code></pre>
  <p>}</p>
  <p>some user had a problem with this file <code>l10n.php</code></p>
  <p><a href="https://wordpress.org/support/topic/l10n-php137-crashes-entrie-website/" rel="nofollow noreferrer">https://wordpress.org/support/topic/l10n-php137-crashes-entrie-website/</a></p>
  <p>i've change for a fresh file but don't work.</p>
  <p>I will try to install wordpress 5.5.1</p>
  <p>Somebody have a workaround technic ? Many thanks</p>