php htmlspecialchars并没有工作

I have this simple code :

$handle = fopen($file,"r");
$html_file=fread($handle,filesize($file));
fclose($handle);

echo htmlspecialchars($html_file);

and the second problemhtmlspecialchars, it working correctly if the file in English but when the file have Hebrew text it don't echo anything and don't give me any errors

when I echo $html_file it working ok, so the problem only when I use htmlspecialchars() does anyone have any Idea why this happen ?