Issue #2459873 by borisson_, swentel: FieldStorageConfig::__sleep() should unset ->original

core/lib/Drupal/Core/Field/FieldConfigBase.php

@@ -398,7 +398,7 @@ public function __sleep() {
     // Only serialize necessary properties, excluding those that can be
     // recalculated.
     $properties = get_object_vars($this);
-    unset($properties['fieldStorage'], $properties['itemDefinition'], $properties['bundleRenameAllowed']);
+    unset($properties['fieldStorage'], $properties['itemDefinition'], $properties['bundleRenameAllowed'], $properties['original']);
     return array_keys($properties);
   }
 

core/modules/field/src/Entity/FieldStorageConfig.php

@@ -694,7 +694,7 @@ public function __sleep() {
     // Only serialize necessary properties, excluding those that can be
     // recalculated.
     $properties = get_object_vars($this);
-    unset($properties['schema'], $properties['propertyDefinitions']);
+    unset($properties['schema'], $properties['propertyDefinitions'], $properties['original']);
     return array_keys($properties);
   }