无法为ie8生成ical事件：'无法从mywebsite.com下载file.aspx。 无法打开该网站...'

Question

I'm trying to send an ical appointment as an http response to my users. It works great in Chrome and IE9, but on IE8 (using windows xp at least) throws a popup error message 'Unable to download file.aspx from mywebsite.com. Unable to open this internet site. the requested site is either unavailable or cannot be found. please try again later.'

How can I resolve this?

I've tried playing around with the cache control header and MIME type, but haven't found a solution yet.

Here is the raw HTTP response from my web server:

HTTP/1.1 200 OK
Cache-Control:  no-cache, no-store, must-revalidate
Pragma: no-cache
Content-Type:   text/calendar; charset=UTF-8
Content-Language:   en-US
Expires:    -1
Server: Microsoft-IIS/7.5
Set-Cookie: ASP.NET_SessionId=yndoq4voisfn03nkt1o3zluk; path=/; HttpOnly
Set-Cookie: VisitorStatus=11058043496; expires=Tue, 07-Sep-2032 15:16:44 GMT; path=/; HttpOnly
Content-Disposition:    attachment; filename=Webinar.ics
X-AspNet-Version:   4.0.30319
X-Powered-By: ASP.NET
Date:   Fri, 07 Sep 2012 15:16:44 GMT
Connection: close
Content-Length: 1409

BEGIN:VCALENDAR
VERSION:2.0
METHOD:PUBLISH
PRODID:-//ddaysoftware.com//NONSGML DDay.iCal 1.0//EN
BEGIN:VEVENT
DESCRIPTION:test1\ntest2
DTEND:20120914T160000
DTSTAMP:20120907T151644Z
DTSTART:20120914T150000
LOCATION:Webinar - See information below for the link and dial in informati
on
ORGANIZER:mailto:CommunityManager@mysite.net
SEQUENCE:0
SUMMARY:Charting Your Career Path Amidst Healthcare Reform.
UID:00000000-0000-0000-0000-000000000000
BEGIN:VALARM
ACTION:Display
DESCRIPTION:Reminder
DURATION:PT15M
TRIGGER:PT15M
END:VALARM
END:VEVENT
END:VCALENDAR

I found that this does work on someone else's website... so here's their raw response if it helps any.

HTTP/1.0 200 OK
Date:   Fri, 07 Sep 2012 15:06:08 GMT
Server: Apache
Content-Language: en-US
Content-Disposition: attachment; filename=webinar.ics
Connection: close
Content-Type: text/calendar; charset=UTF-8

BEGIN:VCALENDAR
VERSION:2.0
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Pacific Time (US & Canada)
BEGIN:STANDARD
DTSTART:20061105T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=11
TZOFFSETFROM:-0700
TZOFFSETTO:-0800
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:20070311T020000
RRULE:FREQ=YEARLY;BYDAY=2SU;BYMONTH=3
TZOFFSETFROM:-0800
TZOFFSETTO:-0700
TZNAME:Daylight Savings Time
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=”Pacific Time (US & Canada)”:20120912T090000
DTEND;TZID=”Pacific Time (US & Canada)”:20120912T100000
LOCATION;ENCODING=QUOTED-PRINTABLE:Webinar - See conference call information below
UID:200000000013097050
DTSTAMP:20120907T150608Z
DESCRIPTION:1. Click this link to start or to join the Webinar:\n\n       https://www3.gotomeeting.com/ojoin/\n\n\n2. Choose one of the following audio options:\n\n   TO USE YOUR COMPUTER’S AUDIO:\n   When the Webinar begins, you will be connected to audio using your computer’s microphone and speakers (VoIP). A headset is recommended.\n\n\n   TO USE YOUR TELEPHONE:\n   If you prefer to use your phone, you must select “Use Telephone” after joining the Webinar and call in using the numbers below.\n\n\n   Toll-free: 1 877 568 4108\n   Toll: +1 (951) 266-6130\nAccess Code: 70\n   Audio PIN: Shown after joining the meeting\n\n\nGoToWebinar®\nWebinars Made Easy™\n
SUMMARY;ENCODING=QUOTED-PRINTABLE:Charting Your Healthcare Career
BEGIN:VALARM
TRIGGER:-PT15M
ACTION:DISPLAY
DESCRIPTION:Reminder
END:VALARM
END:VEVENT
END:VCALENDAR

Answer 1

I had been sending users the link to this calendar request directly in an email. I was having trouble figuring it out, so I changed it to link to a landing page where users could then click on a link to generate the calendar invitation. It solved the problem. Other solutions welcome!