I get this error as well. If i make some changes to an existing post and hit “Update” or create a new post and hit “Publish” the error occurs.
Doing a debug_backtrace, it seems to originate from acf_verify_nonce() in api/api-helpers.php where wp_verify_nonce() is called on line 1034. The value of $_POST[‘_acfnonce’] is an int with the ID of the post. The error disappears if i typecast it to a string by changing line 1034 to
if( wp_verify_nonce((string)$_POST['_acfnonce'], $nonce) ).
This is kind of the same solution as @jurajk proposed in the previous post but it feels better to edit a plugin than WP core 🙂 It might even cause a security issue since we are validating nonces. Someone with more insight can maybe shed a light on this.
@elliot Whether the error originates from another plugin or if it’s ACF that causes the problem in the first place I do no know but if you want some more info about my setup, I’d be happy to provide it.
Thanks for an awesome, game changing, plugin!
