html post请求google浏览器报405
下面是一段简单的表单标签
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>HTML-表单</title>
</head>
<body>
<form action="" method="post">
用户名:<input type="text" name="username">
年龄:<input type="text" name="age">
<input type="submit" value="提交">
</form>
</body>
</html>
点击提交,报错
请问该如何解决,凡是涉及“post”操作都报一样的错误