页面跳转报错 This request has been blocked； the content must be served over HTTPS

JS 报错：
This request has been blocked; the content must be served over HTTPS

详细报错

详细报错内容如下：

Mixed Content: The page at 'https://xxx/mainfrane' was loaded over HTTPS, but requested an insecure forn action 'http://xxx/student/exan'. This request has been blocked; the content must be served over HTTPS.

报错原因

http、https 混合导致的

网站用的是 https 要跳转到 http 请求，被阻止了。

解决方法

1. 页面中都是用 https ，或者都使用 http

2. 在 标签中添加以下代码

<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests"/>

意思是自动将 http 的不安全请求升级为 https。