mixed content the site was loaded over a secure connection but the file at was loaded over an insecure connection

problem

问题: 在https地址试图通过a标签跳转到http下载地址时，浏览器报错
mixed content the site https://xxx was loaded over a secure connection but the file at http://yyy was loaded over an insecure connection

reason

原因

• 推测是触发了 chrome 安全检查
• “Mixed Content” warnings occur when an HTTPS page is asked to load a resource over HTTP.

测试发现

• chrome 浏览器控制台会报错
• firefox 浏览器不会报错
• 手机自带浏览器也不会报错

solution

将跳转地址http改为https

<!-- 这个方法不可用 -->
<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests">