SVG animation is not working on IE11

Only Microsoft Edge will support SVG CSS Transitions and Animation.. especially stroke-dasharray.

Please see the Microsoft Developer Docs:

https://dev.windows.com/en-us/microsoft-edge/platform/status/csstransitionsanimationsforsvgelements

Allows CSS Transitions and Animations to apply to SVG elements.
Unprefixed version: Microsoft Edge build 10240+

As you can see in my fork of your example. You were not seeing the loader spin due to not having the stroke attribute on your circle element.

http://jsfiddle.net/z8w4vuau/50/

You can see how it can spin now. But you will have to check if the browser is IE and adjust your stroke-dasharray so it is larger dash. Since IE11 and below do not support animating SVG stroke-dasharray and stroke-dashoffset with CSS animation or transitions, unless it is Microsoft Edge build 10240+.\

But if you need a cross browser solution to animate SVG, especially stroke-dasharray and stroke-dashoffset. Then look into using a JS animation library like the GreenSock Animation Platform (GSAP). Using the DrawSVGPlugin

http://greensock.com/drawSVG

IE does not support CSS animation of SVG elements. It also doesn't support the standard built-in SMIL animations that SVG has.

If you convert your animation to native SVG animations, you could perhaps get it working using the FakeSmile library. Otherwise you will need to use some alternative fallback for IE - such as an animated gif or something.