Internet Explorer 11 does not display rich site summary (RSS) sites such as Feedburner in the feed view as expected. In this situation, you can't subscribe to the feed in Internet Explorer 11.
The RSS site passes the nosniff header, but is specified with the incorrect mime type (text/xml, application/xml). However, Internet Explorer 11 should ignore the nosniff header on the site.
To resolve this issue, install the most recent cumulative security update for Internet Explorer. To do this, go to Microsoft Update.
This update was first included in the following security update:
2909921 MS14-010: Cumulative security update for Internet Explorer: February 11, 2014
For technical information about the most recent cumulative security update for Internet Explorer, go to the following Microsoft website:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
See the terminology that Microsoft uses to describe software updates.