This request has been blocked； the content must be served over HTTPS._html

 Mixed Content: The page at 'xxxxxx' was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint 'http://xxxxxx'. This request has been blocked; the content must be served over HTTPS.

解决办法：

在HTML中的head标签中添加下面代码，即可解决此问题。

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