Alternate CSS URL - Error when mapping to another site collection

Question

I have created a .css file which I have attached on the root Site Collection (https://intranet.domain.com.au) using Site Settings> Master Page> Alternate CSS URL> Specify a CSS... and I have attached
my file.  So, that all works fine.
I have then tried to attach this CSS file on another site collection - say
https://intranet.domain.com.au/sites/Site - but when I browse to this site, I get IE saying
"Only Secure Content is Displayed".
I did find a TechNet article saying to change browser settings in Security> Trusted Sites> Custom Level> Display Mixed Content> Enable - but this didn't seem to make any difference.
I would prefer to map just the one CSS file so that when any changes are made, it replicates to this site collection.
Any pointers?

Answer 1

Hi,
If you would like to apply one CSS file to multiple sites, here are two methods you could use:
1.      
Place the css file in layout folder, and apply it in master page
http://sharepoint.stackexchange.com/questions/81372/alternate-css-url-point-to-layouts-15-folder
2.      
Place the css file in layout folder, and create a solution with control element
http://sharepoint.stackexchange.com/questions/75480/what-is-the-proper-way-to-add-custom-css-javascript-sharepoint-2013-site
For more information:
http://www.ashokraja.me/post/Refer-Scripts-and-CSS-Style-Sheet-in-SharePoint-2013-Visual-Web-Part-and-Master-Page.aspx
Regards,
Rebecca Tu
TechNet Community Support