I'm having trouble importing an ics file via the 'internet calendars' option in Outlook. The file is produced, I believe, by a Java applet. When I open the ics file directly within Outlook 2010 it works fine, i.e. click on the link and open the downloaded file with Outlook. I've also validated it online with the validator mentioned in some Stack Overflow posts. However when I subscribe to the link via internet calendars I get the following error: The file "calendar" is not a valid Internet Calendar file I haven't been able to work out what's going wrong here and the error message isn't particularly helpful. Does anyone have any ideas why this isn't working?