Ticket #26280: 26280.patch

wp-admin/css/wp-admin.css

@@ -1920 +1920 @@
 /* Sticky admin menu */
 .sticky-menu #adminmenuwrap {
         position: fixed;
-        z-index: 99; /* Match the z-index of .wp-submenu to ensure flyout menus don't appear underneath main column elements */
+        z-index: 999; /* Match the z-index of .wp-submenu to ensure flyout menus don't appear underneath main column elements */
 }
 
 /* A new arrow */