Advanced Custom Fields Pro 6.4.0.1

Flexible Content: Added logic to better clean up data when re-ordering layouts
oEmbed field: Fixed bug causing incorrect width and height settings in embed HTML
Core: Fixed bug causing incorrect Select2 CSS version loading for WooCommerce 2.7
Core: Fixed bug preventing min-height style being applied to floating width fields
Core: Added new JS init actions for wysiwyg, date, datetime, time and select2 fields
Core: Minor fixes and improvements

* Core: Fixed bug causing `get_field()` to return incorrect data for sub fields registered via PHP code.

5.5.6

• Core: Fixed bug causing license key to be ignored after changing url from http to https
• Core: Fixed Select2 (v4) bug where allow null setting would not correctly save empty value
• Core: Added new acf/validate_field filter
• Core: Added new acf/validate_field_group filter
• Core: Added new acf/validate_post_id filter
• Core: Added new row_index_offset setting
• Core: Fixed bug causing value loading issues for a taxonomy term in WP < 4.4
• Core: Minor fixes and improvements