Index: branches/5.1.x/core/admin_templates/categories/categories_edit.tpl
===================================================================
diff -u -N -r13168 -r13461
--- branches/5.1.x/core/admin_templates/categories/categories_edit.tpl	(.../categories_edit.tpl)	(revision 13168)
+++ branches/5.1.x/core/admin_templates/categories/categories_edit.tpl	(.../categories_edit.tpl)	(revision 13461)
@@ -213,6 +213,8 @@
 			reflectCachingSettings();
 		}
 	);
+
+	disable_categories('<inp2:c_InputName name="ParentId"/>', <inp2:c_AllowedCategoriesJSON/>);
 </script>
 
 <inp2:m_include t="incs/footer"/>
\ No newline at end of file