update

wp-content/plugins/youtube-feed-pro/activation.php

@@ -0,0 +1,36 @@
+<?php
+
+if (!function_exists('sby_on_plugin_activation')) {
+    function sby_on_plugin_activation($plugin)
+    {
+        if (basename($plugin) !== 'youtube-feed.php') {
+            return;
+        }
+
+        $plugin_to_deactivate = 'feeds-for-youtube';
+        if (false !== strpos($plugin, $plugin_to_deactivate)) {
+            $plugin_to_deactivate = 'youtube-feed-pro';
+        }
+
+        foreach (sby_get_active_plugins() as $basename) {
+            if ($basename === $plugin_to_deactivate . '/youtube-feed.php') {
+                deactivate_plugins($basename);
+
+                return;
+            }
+        }
+    }
+
+    function sby_get_active_plugins()
+    {
+        if (is_multisite()) {
+            $active_plugins = array_keys((array)get_site_option('active_sitewide_plugins', array()));
+        } else {
+            $active_plugins = (array)get_option('active_plugins', array());
+        }
+
+        return $active_plugins;
+    }
+}
+
+add_action('activated_plugin', 'sby_on_plugin_activation');