Got a meeting request that borked Outlook, so I started a-googlin'. Here's the easily found Microsoft support article:

The "not supported calendar message.ics" attachment is created when the original .ics file cannot be converted to an Outlook or Microsoft Exchange meeting type. The conversion fails if one or more of the following conditions are true:

  1. The meeting contains a recurrence pattern that is available to a third-party email client, such as Lotus Notes. However, this recurrence pattern is not supported by Outlook:
  2. Monthly by Date: Every month on the nth day and the nth day. Outlook only supports one nth day of the month.
  3. Monthly by Day: Every month on the nth day of the week and the nth day of the week. Outlook only supports one nth day of the week in any month.
  4. Custom recurrence: Outlook does not support custom recurrence patterns that are available in some third-party email clients, such as Lotus Notes.
  5. The meeting contains a recurrence pattern that is defined by the RDATE property. However, the meeting does not include a corresponding RRULE property. In this case, Outlook does not open the item, even if the RDATE property specifies a supported recurrence pattern

How do you fix problem 1? Oh, so glad you asked! It's easy!

To work around this issue, have the meeting organizer create a meeting that uses a recurring pattern that Outlook supports.

Or, if it's problem 2., it's even more fun! You can go read an RFC.

For more information about the RDATE and RRULE properties, visit the following page on The Internet Engineering Task Force (IETF) website:

Wow. The worst part of this is the date of the last update to this support article.

Article ID: 2643084 - Last Review: November 9, 2011 - Revision: 2.0

These don't seem like particularly difficult thing to kludge around. How is it that such an easily definable set of edge cases can't be kludged into Outlook 2010 at some point in the last three and a half years? Are there really that many more important issues? Sounds like this could be fixed in a good weekend of work, plus a few hours of QA. Release it as an unsupported script or translation utility, for heaven's sake.


Outlook fail.

Update: ExQuilla imported the ics file, no problems.