update

wp-content/plugins/youtube-feed-pro/vendor/smashballoon/customizer/app/ProxyProvider.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Smashballoon\Customizer;
+
+/** @internal */
+abstract class ProxyProvider
+{
+    public function get_settings_class()
+    {
+    }
+    public function get_db_settings()
+    {
+    }
+}