diff --git a/administrator/components/com_admin/script.php b/administrator/components/com_admin/script.php
index e4d9a4c1e7c0e..1b8e977a56b0d 100644
--- a/administrator/components/com_admin/script.php
+++ b/administrator/components/com_admin/script.php
@@ -2350,7 +2350,9 @@ protected function fixFilenameCasing()
                     }
                 } else {
                     // On Unix with both files: Delete the incorrectly cased file.
-                    File::delete(JPATH_ROOT . $old);
+                    if (is_file(JPATH_ROOT . $old)) {
+                        File::delete(JPATH_ROOT . $old);
+                    }
                 }
             }
         }
diff --git a/libraries/src/Updater/Adapter/ExtensionAdapter.php b/libraries/src/Updater/Adapter/ExtensionAdapter.php
index 4f494e9eacdcc..2314254c1ebe8 100644
--- a/libraries/src/Updater/Adapter/ExtensionAdapter.php
+++ b/libraries/src/Updater/Adapter/ExtensionAdapter.php
@@ -29,6 +29,9 @@
  */
 class ExtensionAdapter extends UpdateAdapter
 {
+    protected $currentUpdate;
+    protected $latest;
+
     /**
      * Start element parser callback.
      *
diff --git a/libraries/src/Updater/Update.php b/libraries/src/Updater/Update.php
index b77a61875c51f..553eb729036c3 100644
--- a/libraries/src/Updater/Update.php
+++ b/libraries/src/Updater/Update.php
@@ -232,6 +232,11 @@ class Update
      * @since  3.10.2
      */
     protected $compatibleVersions = [];
+    protected $downloadurl;
+    protected $tag;
+    protected $stability;
+    protected $supported_databases;
+    protected $php_minimum;
 
     /**
      * Gets the reference to the current direct parent