Wikimedia Bugzilla is closed!

I've run the basic install on 1.11.1. The only trouble I've had so far is that after clicking on the trackback link, I get the following error

XML Parsing Error: xml declaration not at start of external entity
Location: http://url/trackback.php?article=Main_Page
Line Number 2, Column 1:<?xml version="1.0" encoding="utf-8"?>
^

Everything I've been able to gather about this error online states that this is the product of whitespace characters or blank lines before or after the xml declaration tags, however I've checked and confirmed that there aren't any. It's the stock trackback with the tarball. 

function XMLsuccess() {
header("Content-Type: application/xml; charset=utf-8");
echo "
<?xml version=\"1.0\" encoding=\"utf-8\"?>
<response>
<error>0</error>
</response>
        ";
        exit;
}
function XMLerror($err = "Invalid request.") {
        header("HTTP/1.0 400 Bad Request");
        header("Content-Type: application/xml; charset=utf-8");
        echo "
<?xml version=\"1.0\" encoding=\"utf-8\"?>
<response>
<error>1</error>
<message>Invalid request: $err</message>
</response>
";
                exit;
}