Issue #3379409 by fjgarlin, NickDickinsonWilde: Not handling old file correctly - AdvAgg

src/Entity/DocBlock.php

@@ -328,7 +328,7 @@ class DocBlock extends ContentEntityBase implements DocBlockInterface {
    * {@inheritdoc}
    */
   public function getCode() {
-    return $this->get('code')->value;
+    return $this->get('code')->value ?? '';
   }
 
   /**