If you have "Mollie Payments for WooCommerce" plugin activated, the frontend Builder will not load the modules correctly. There are a lot of console errors caused by the plugin. Once you disable the plugin, the frontend Builder will load properly. If you experience this issue, please report to the plugin's author. As a temporary solution, you can disable that plugin when you need to edit the frontend Builder. Reference: https://themify.me/forum/topic/issue-builder-with-mollie-payments#post-938187
