Changed the begin.eui bootstrap process to let the VWF have the initialization back. In other words to not do anything there that could take time to complete like make an ajax call which causes hanging currently, especially if it fails. Now the config json is loaded via script tag, although the VWF is controlling it and loading it using jQuery and not the browser. so a tail ajax request still counts there. That means your <script> sources must not result in a 404. Installers should copy eui-defaults.json.js to eui.json.js and modify it as needed.