diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 107ca9a..7fd74ec 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2210,10 +2210,6 @@ function _drupal_exception_handler($exception) {
  * Sets up the script environment and loads settings.php.
  */
 function _drupal_bootstrap_configuration() {
-  // Set the Drupal custom error handler.
-  set_error_handler('_drupal_error_handler');
-  set_exception_handler('_drupal_exception_handler');
-
   drupal_environment_initialize();
   // Start a page timer:
   timer_start('page');
@@ -2228,6 +2224,11 @@ function _drupal_bootstrap_configuration() {
 
   // Load the procedural configuration system helper functions.
   require_once DRUPAL_ROOT . '/core/includes/config.inc';
+
+  // Set the Drupal custom error handler. (requires config())
+  set_error_handler('_drupal_error_handler');
+  set_exception_handler('_drupal_exception_handler');
+
   // Redirect the user to the installation script if Drupal has not been
   // installed yet (i.e., if no $databases array has been defined in the
   // settings.php file) and we are not already installing.
diff --git a/core/includes/errors.inc b/core/includes/errors.inc
index 5fc4b7d..5511262 100644
--- a/core/includes/errors.inc
+++ b/core/includes/errors.inc
@@ -153,14 +153,46 @@ function _drupal_render_exception_safe($exception) {
  *   TRUE if an error should be displayed.
  */
 function error_displayable($error = NULL) {
-  $error_level = config('system.logging')->get('error_level');
-  $updating = (defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'update');
-  $all_errors_displayed = ($error_level == ERROR_REPORTING_DISPLAY_ALL) ||
-    ($error_level == ERROR_REPORTING_DISPLAY_VERBOSE);
-  $error_needs_display = ($error_level == ERROR_REPORTING_DISPLAY_SOME &&
-    isset($error) && $error['%type'] != 'Notice' && $error['%type'] != 'Strict warning');
+  global $conf;
 
-  return ($updating || $all_errors_displayed || $error_needs_display);
+  // For maintenance scripts, all errors are displayed.
+  if (defined('MAINTENANCE_MODE')) {
+    return TRUE;
+  }
+  // The current bootstrap situation and availability of configuration system
+  // services is unknown, so we take extra care in trying to retrieve the
+  // configured error_level value.
+  try {
+    $container = drupal_container();
+    if ($container) {
+      // If there is a service container, any of the following calls to get()
+      // methods may throw an exception, but there won't be a fatal error, since
+      // we catch it.
+      $error_level = $container->get('config.factory')->get('system.logging')->get('error_level');
+    }
+  }
+  catch (\Exception $e) {
+    // In order to additionally guard against a configured but bogus NULL or
+    // empty value, we unconditionally apply the fallback logic below.
+  }
+  // Try fallback values if the config object does not exist or cannot be loaded.
+  if (empty($error_level)) {
+    // Check whether settings.php defines a value.
+    if (isset($conf['system.logging']['error_level'])) {
+      $error_level = $conf['system.logging']['error_level'];
+    }
+    // Otherwise, default to ERROR_REPORTING_DISPLAY_ALL.
+    else {
+      $error_level = ERROR_REPORTING_DISPLAY_ALL;
+    }
+  }
+  if ($error_level == ERROR_REPORTING_DISPLAY_ALL || $error_level == ERROR_REPORTING_DISPLAY_VERBOSE) {
+    return TRUE;
+  }
+  if ($error_level == ERROR_REPORTING_DISPLAY_SOME) {
+    return isset($error) && $error['%type'] != 'Notice' && $error['%type'] != 'Strict warning';
+  }
+  return FALSE;
 }
 
 /**