ICalendar and Outlook opeing as node For Add to Cal Module Even After Clearing Caches I installed the Add to cal module and enabled it.

Created a View using with fields or Event Date,Location and Title.

Thus when I added Event Date fields to the View and While Configuring i Choosed Formatter to Add to Cal.
The Add to Cal Works fine For Google and Yahoo calendar But When I choose The ICalendar or Outlook Option , corresponding node file gets open eg:- [website name]/node/207/field_date1/addtocal.ics but doesnt downloads the ics file.

I tried Clearing the Cache Varnish Cache as it hosted on the Acquia.com and also the Performance cache but that seems to not work.
I'm a maintainer of the Add To Cal module. It turns out that this is in fact a bug, which we're patching right now.

Until the patch is released, you can fix the issue by downloading and enabling the Entity module on your site. The patch will add this as a dependency to Add To Cal.

Here's the issue on drupal.org: https://www.drupal.org/node/1744684#comment-9056553

EDIT: The 1.x-dev version now includes this bug fix, and it will be included in the beta4 release.