Environment: MS Edge on Windows 10 vm from modern.ie http://dev.modern.ie/tools/vms/mac/
Material Icons are not being displayed. I was able to reproduce by visiting the preview of the blog template:

EDIT:
Confirmed not displaying when defining the icon as:
<i class="material-icons">add</i>
Does display when defining the icon as:
<i class="material-icons"></i>
Not sure anything can be done about this as it may be a MS Edge "feature."
can't reproduce on windows 10 running on real hardware.
test if that page works:
https://www.google.com/design/icons/
This an open issue with the font https://github.com/google/material-design-icons/issues/179
@surma Should we add the fix in https://github.com/google/material-design-icons/issues/179#issuecomment-132168462 or will we wait for this to be fixed upstream?
@sgomes I guess fixing it on our side can do no harm. I鈥檒l run a test shortly
This is actually related to http://stackoverflow.com/questions/32061829/microsoft-edge-user-agent-from-modern-ie/32102663#32102663. Long story short, it's a bug with the modern.ie VM, which is providing the wrong useragent, and thus not getting the full CSS from Google Fonts. Switching your modern.ie VM to a non-mac version or using a real Windows 10 install should fix it.
Most helpful comment
This is actually related to http://stackoverflow.com/questions/32061829/microsoft-edge-user-agent-from-modern-ie/32102663#32102663. Long story short, it's a bug with the modern.ie VM, which is providing the wrong useragent, and thus not getting the full CSS from Google Fonts. Switching your modern.ie VM to a non-mac version or using a real Windows 10 install should fix it.