try to add cancel button

app/UI/Reinstall/Pages/ReinstallTab.php

@@ -36,6 +36,6 @@ class ReinstallTab extends TabsWidget implements ClientArea, AdminArea
     {
         $this->addElement(new TemplateRawDataTable());
         //$this->addElement(new IsoRawDataTable());0
-        $this->addActionButton(new BaseCancelButton());
+        $this->addElement(new BaseCancelButton());
     }
 }