New error since yesterday on html's.

Hi w3c,
I’m using your online tool https://validator.w3.org/#validate_by_upload to check html files. Thanks for your good work, it’s so useful for me.
Since this morning I’m getting this error when I check the files:
Error: --!> found at end of comment (should just be -->).
At line 11, column 16
<![endif]-->↩ </div>↩ </bo

Yesterday my html were valid, but now the same HTML is not valid and I don’t understand the error. Did you implement new checks on the tool?
I can’t send you the address or the original html, but this example of code works good to get the error (check it with HTML5 doctype):
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>test</title>
</head>
<body>
<div id="ARQpie">
    <!--[if lte IE 8]>
    <a href="#" title="test" style="display:block;"></a>
    <![endif]-->
</div>
</body>
</html>
Best regards.
Alfredo.

Received on Monday, 22 May 2017 22:19:13 UTC