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)
