One of ACF’s function is returning false when looking by field name. What you’re going to need to do is check to see if the field has a value before attempting to delete it.
function delete_field( $selector, $post_id = false ) {
// filter post_id
$post_id = acf_get_valid_post_id( $post_id );
// get field
$field = acf_maybe_get_field( $selector, $post_id );
// delete
return acf_delete_value( $post_id, $field );
}
acf_maybe_get_field() is returning false
acf_delete_value() expects $field to be an array, which it is not.
The last line of this function should likely be
if ($field) {
return acf_delete_value( $post_id, $field );
}
of the function acf_delete_value() should be checking to see if $field has a value before attempting to use it.
I would call this a bug. You should submit it here https://www.advancedcustomfields.com/contact/
In the mean time, as a fix, you can either use the field key when calling these or check for a value.
I would use the field key because as I already mentioned update_field() using the field name where the field does not already have a value will fail to save a value. This is covered in the documentation for this function https://www.advancedcustomfields.com/resources/update_field/
