Unsafe attempt to load URL svg

This page has all the answers, I believe :

https://css-tricks.com/svg-use-external-source/

• It just doesn't work on IE unless you use a polyfill.
• Comments down the page describe the issue on Chrome when running locally :

you can run into some cross-domain issues with this technique when developing locally, if you aren’t developing with a server.

As I wrote on davidwells.io (on this page is also his Javascript solution of the problem):

I had the same problem when I used external SVG file. I had to change configuration of virtual server and stop automatic redirecting SVG requests from HTTP to HTTPS. Other words: SVG file must be available on both of protocols. Now it working.