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.
%S 提交的一个表单不能编码所有的 Unicode 字符，所以用户输入的内容可能损坏。要想避免这个问题，应变更表单以 UTF-8 编码提交，或者通过改变页面本身的编码到 UTF-8，再或者指定表单元素的接受字符集到 UTF-8（accept-charset=utf-8）。