[SOLVED] UTF8 Character Error

Have just upgraded a site to current versions, WordPress 3.8.1, and Atahualpa 3.7.13

In Body, Text & Links > Body Style, the following now appears:

<br />
<b>Warning</b>: htmlspecialchars() [<a href='function.htmlspecialchars'>function.htmlspec ialchars</a>]: charset `utf8_general_ci' not supported, assuming iso-8859-1 in <b>/home/harmony/public_html/content/wp-includes/formatting.php</b> on line <b>3019</b><br />
<br />
font-family: "Palatino", "Georgia", "Times New Roman", "Times", serif;
font-size: 1.0em;
line-height: 1.4em;
color: #ebebeb;
background: url(/content/wp-content/ata-images/background.jpg) repeat top left;
padding-top: 10px; padding-bottom: 10px;


Those first lines, between the <br /> tags, are being added. Deleting them and saving the options has no effect; they automatically come back when I view this page again.

The website: http://www.americachinabridge.com

Things to consider:

1. I have not modified formatting.php, so the standard WP file is functioning. No other WP files, or Ata files, have been modified, they are all standard-issue.

2. This site uses WPML to manage multiple languages, in this case English and Mandarin Chinese. WPML is fully upgraded, to the current version, 2.8.1

3. In the MySQL database encoding, PHPMyAdmin reports Server connection collation as utf8_general_ci - which has always worked fine with the Atahualpa and WP combo.

4. Note also that Chinese language characters being interpreted through the theme, like the blog title and subtitle, are being shown as ASCII garbage; see the header area on any page of http://www.americachinabridge.com, and the language switcher widget on the right sidebar.

What is happening here? Please help.