I have a callback function that check_captcha which sees if $row is ==0 or == 1 (this information is queried from sql).
The p
Actually the best way, instead of write the error message directly on controller, would be add this entry "check_captcha" on languages.
In my case, the message for validation rule (form validation) "less_than" was not present.
I changed the file /system/language/??/form_validation_lang.php. I've added the missing entry.