Awesome, this fix is working for me. The snippet starts on line 1055 in /wp-content/themes/plugins/themify-builder/js/themify.builder.admin.ui.js (for the plugin, will be different path for themes)
I’ve been having the same problem since mid-May. I just turned on debugging and this showed up in the log when I tried to save a post:
[15-Jul-2015 21:28:11 UTC] PHP Notice: Trying to get property of non-object in /web/tcr/wp-content/plugins/themify-builder/classes/class-themify-builder.php on line 613
and that line is:
‘post_ID’ => $post->ID,
Themify’s builder component is included in their free themes at http://themify.me/themes/free-themes
ACF Pro v5.2.7
Builder v1.3.8
WP 4.2.2
PHP 5.6.10
MySQL 5.5.42
Has also been reported on their support site at http://themify.me/forum/topic/acf-plugin-and-active-builder-module-dont-save-pagesposts (requires login)
Same issue here with 5.2.0, and rolling back seems to remove all custom fields configuration. Yay!
Same issue using the Post Object type with 4.3.3 and WP 3.8. I set it to show all types and everything except pages were included. Downgrading to 4.3.2 got it working again.