Fix editing system pages

diff --git a/wcfsetup/install/files/lib/acp/form/PageAddForm.class.php b/wcfsetup/install/files/lib/acp/form/PageAddForm.class.php
index c4b6260c5fa444642ad878cc21ed78459d57a080..538482914e4496934d5549c114ae5aee46bb5ad3 100644 (file)
--- a/wcfsetup/install/files/lib/acp/form/PageAddForm.class.php
+++ b/wcfsetup/install/files/lib/acp/form/PageAddForm.class.php
@@ -212,7 +212,7 @@ class PageAddForm extends AbstractForm
      * @var bool
      * @since   5.4
      */
-    public $invertPermissions;
+    public $invertPermissions = 0;
 
     /**
      * @inheritDoc