This below message occurs when you attempt to view a web page using https that contains images (other items) linked using http. This is NOT a server issue. This is a coding issue and you should modify your html/php page's code as shown below...
INCORRECT way of linking images, that causes the error message:
<img src="http://domainname.com/images/image1.gif"> ==> "http" is causing the problem here
CORRECT way of linking images should be:
==> Use "https" instead of "http"
--- OR ---
==> Use relative path instead of absolute path
Note: This issue will happen ONLY when you try to access your pages thru SSL (https).