Hi Venutius,
I would like to analyze the described behavior together with you. Could I get in direct contact with you for a fast solution?
You can contact me at [email protected]
Awesome – works like a charm. Thank you for your instant assistance!
I found the bug. On your validation example page it states
add_filter('mc4wp_form_message', 'myprefix_add_mc4wp_error_message');
But it would have to be
add_filter('mc4wp_form_messages', 'myprefix_add_mc4wp_error_message');
^
After digging into MC4WP’s code I found the difference. Please correct the example code on your website accordingly. I close this ticket.
Have a great day!