A form was submitted in the %S encoding which cannot encode all Unicode characters, so user input may get corrupted. To avoid this problem, the page should be changed so that the form is submitted in the UTF-8 encoding either by changing the encoding of the page itself to UTF-8 or by specifying accept-charset=utf-8 on the form element.
Enviouse un formulario coa codificación %S na que non é posíbel codificar todos os caracteres Unicode, polo que a entrada do usuario pode obterse corrupta. Para evitar este problema, debería cambiarse a páxina para que se envíe o formulario na codificación UTF-8, ou cambiando a codificación da páxina a UTF-8 ou especificando accept-charset=utf-8 no elemento do formulario.