验证以下html时，我收到以下错误消息
错误：在此上下文中，元素内容不允许作为元素主体的子级。（禁止从此子树中进一步出现错误。）从第41行第1列开始；至第41行第9列↩↩ <图元主体的内容模型：流量内容。
有人能澄清一下这意味着什么以及如何消除这个错误吗？？谢谢：-）
<body>
<header>
<div class="header-wrapper">
<div class="header-bg"></div>
<div class="header-content">
<ul>
<li class="instagram">
<a href="" class="navBarLinks find">Find me on</a>
<a href="" class="navBarLinks in">
<svg class="insticon" version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" viewBox="0 0 155.2 144" style="enable-background:new 0 0 155.2 144;" xml:space="preserve">
<style type="text/css">
.st0 {}
</style>
<path class="st0" d="M50.1,121.7H28.8V53h21.4V121.7z M39.4,43.6c-6.8,0-12.4-5.6-12.4-12.4s5.5-12.4,12.4-12.4
c6.8,0,12.4,5.5,12.4,12.4C51.8,38,46.3,43.6,39.4,43.6z M130.1,121.7h-21.3V88.3c0-8-0.1-18.2-11.1-18.2
c-11.1,0-12.8,8.7-12.8,17.6v34H63.5V53H84v9.4h0.3c2.8-5.4,9.8-11.1,20.2-11.1c21.6,0,25.6,14.2,25.6,32.7
C130.1,84,130.1,121.7,130.1,121.7z" />
</svg>
</a>
</li>
<li class="home"><a href="" class="navBarLinks">Logo </a>
</li>
<li class="hamburger">
<a href="" id="toggle-menu" class="navBarLinks">
<span id="top" class="burger"></span>
<span id="middle" class="burger"></span>
<span id="bottom" class="burger"></span>
</a>
</li>
</ul>
</div>
</div>
</header>
<content>
<div class="stage stage-0">
<div id="overlay">Overlay Placeholder! </div>
<div id="arrow">
<span class="arrow-bounce"><svg fill="#FFFFFF" height="24" viewBox="0 0 24 24" width="24" xmlns= "http://www.w3.org/2000/svg">
<path d="M7.41 7.84L12 12.42l4.59-4.58L18 9.25l-6 6-6-6z"/>
<path d="M0-.75h24v24H0z" fill="none"/>
</svg>
</span>
</div>
<video class="media-player" loop autoplay src="http://ak9.picdn.net/shutterstock/videos/6236564/preview/stock-footage-cybernetic-brain-zooming-through-eye.mp4" style="width: 100%;height: 100%;object-fit: cover;"
>
</video>
</div>
<div class="stage stage-2">3</div>
<div class="stage stage-4">5</div>
<div class="stage stage-6">7</div>
<div class="stage stage-8">9</div>
<div class="stage stage-10">11</div>
<div class="stage stage-12">13</div>
<div class="stage stage-14">15</div>
<div class="stage stage-16">17</div>
<div class="stage stage-18">19</div>
<div class="stage stage-20">21</div>
<div class="stage stage-22">23</div>
</content>
</body>我假设您使用了验证器的DOCTYPE设置来使用HTML5，因为您在源代码中没有包含一个。
<content>标记已从HTML中弃用。
如果你想使用HTML5标签，你应该使用一个替代的HTML标签，比如<section>或<article>标签，或者如果你不想要的话，可以使用一个普通的旧<div>标签。