diff --git a/core/lib/Drupal/Core/Config/Schema/Mapping.php b/core/lib/Drupal/Core/Config/Schema/Mapping.php
index a250821..a8d6c53 100644
--- a/core/lib/Drupal/Core/Config/Schema/Mapping.php
+++ b/core/lib/Drupal/Core/Config/Schema/Mapping.php
@@ -131,6 +131,11 @@ public function getPropertyDefinitions() {
       $this->propertyDefinitions = array();
       foreach ($this->getAllKeys() as $key) {
         $definition = isset($this->definition['mapping'][$key]) ? $this->definition['mapping'][$key] : array();
+        if (empty($definition)) {
+          debug($this->definition['type']);
+          debug($this->definition['debug']);
+          throw new \InvalidArgumentException(String::format("The configuration property @key.@element doesn't have schema.", array('@key' => $this->getFullName(), '@element' => $key)));
+        }
         $this->propertyDefinitions[$key] = $this->buildDataDefinition($definition, $this->value[$key], $key);
       }
     }
diff --git a/core/lib/Drupal/Core/Config/TypedConfigManager.php b/core/lib/Drupal/Core/Config/TypedConfigManager.php
index f8036ea..1943307 100644
--- a/core/lib/Drupal/Core/Config/TypedConfigManager.php
+++ b/core/lib/Drupal/Core/Config/TypedConfigManager.php
@@ -91,7 +91,9 @@ public function buildDataDefinition(array $definition, $value, $name = NULL, $pa
       if (isset($name)) {
         $replace['%key'] = $name;
       }
+      $definition['debug']['dynamic_type'] = $type;
       $type = $this->replaceName($type, $replace);
+      $definition['debug']['resolved_type'] = $type;
       // Remove the type from the definition so that it is replaced with the
       // concrete type from schema definitions.
       unset($definition['type']);
@@ -135,6 +137,7 @@ public function getDefinition($base_plugin_id, $exception_on_invalid = TRUE) {
       unset($definition['type']);
       $this->definitions[$type] = $definition;
     }
+    $definition['debug']['generic_type'] = $base_plugin_id;
     // Add type and default definition class.
     return $definition + array(
       'definition_class' => '\Drupal\Core\TypedData\DataDefinition',