htmlspecialchars“禁止代码点”验证错误

Question

My php script is getting rows from a MySQL table that contain strings such as the following:

$string = 'ï¼’ã¤ã®ä¹³é…¸èŒã®ç¨';

Is there a way to echo these sorts of strings to the browser without getting "Forbidden code point" when running the document through an HTML5 validator?

I have tried the following:

htmlspecialchars($string);
htmlspecialchars($string, ENT_SUBSTITUTE, 'UTF-8');
htmlspecialchars($string, ENT_DISALLOWED, 'UTF-8');
htmlspecialchars(mb_convert_encoding($string, 'UTF-8');

but all of these expressions still result in the "Forbidden code point" error. The encoding of the webpage is already set to UTF-8 via a meta tag:

<meta charset="UTF-8">

Answer 1

The solution that worked for me was:

htmlspecialchars($string, ENT_SUBSTITUTE | ENT_DISALLOWED);

This converted as many characters as possible to UTF-8 and removed everything else.