My b2evolution Version: Not Entered

Is there some reason why this would generate errors in the body of a post?

<div class="info">
<ul class="galleryh">
<li><a href="#nogo">
<img src="/windows/win7.jpg" alt="#1" title="#1" /></a></li>
<li><a href="#nogo">
<img src="/windows/win8.jpg" alt="#2" title="#2" /></a></li>
<li><a href="#nogo">
<img src="/windows/win9.jpg" alt="#3" title="#3" /></a></li>
<li><a href="#nogo">
<img src="/windows/win10.jpg" alt="#4" title="#4" /></a></li>
<li><a href="#nogo">
<img src="/windows/win11.jpg" alt="#5" title="#5" /></a></li>
<li><a href="#nogo">
<img src="/windows/win12.jpg" alt="#6" title="#6" /></a></li>
<li><a href="#nogo">
<img src="/windows/win13.jpg" alt="#7" title="#7" /></a></li>
</ul>
</div>

With appropriate css in style.css, of course.

I have the code + css in an html file in /public_html, and it works as it should. In a post, it does not.