My Work Calendar iCal is invalid

My Work Calendar iCal is invalid

First, thanks for the new My Work Calendar feature with an iCal feed!

But, I can't the feed to work in my Mac iCalendar program.

When I click the iCal button (with the webcal:// URL), I get taken to iCalendar correctly, and the URL shows in the "subscribe" box correctly. However, when I click subscribe in iCalendar, I then get an error:

Data downloaded from [my calendar URL] is invalid.

I also get the same error when I try to manually paste in the http:// version of the URL.

When I look at the downloaded ICS file, it's empty (0 bytes).