I’m having a problem with my site where I try to edit the pages and when I open a page in the page builder menu everything displays as expected, but nothing is clickable and I get the error "Uncaught TypeError: Cannot read property ‘interval’ of undefined " in the JS console.
This error is in the private _lockPost function in line 55 of fl-builder.js: wp.heartbeat.interval(30);
It worked perfectly well before - I’m not sure what’s causing this. It’s occurred seemingly randomly on another installation as well. It seems that perhaps the heartbeat javascript is not being loaded? Any ideas?
I also tried on another install with disabling all plugins and using twenty ten as the theme and get the same issue. Maybe it is connected to WP Engine as the hosting provider that we use?
We had the same problem with WP Engine as they recently disable the heartbeat feature for non admin page.
After submitting the issue to WP Engine support they released a little plugin to install in the mu-plugins directory where you have to configure exceptions where heartbeat should be activated outside the admin. So just ask them to give you access to this plugin, install it in your mu-plugins directory and configure an exception for “index.php” and Fastline Page Builder will work again…