Fix: Not supported calendar message.ics – Outlook
If you received an email with a “not supported calendar message.ics” message attachment in Microsoft Outlook, it is likely the meeting invite was not converted correctly in the original email client it was sent from. Per Microsoft:
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:
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:
Monthly by Date: Every month on the nth day and the nth day. Outlook only supports one nth day of the month.
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.
Custom recurrence: Outlook does not support custom recurrence patterns that are available in some third-party email clients, such as Lotus Notes.
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
- Ask the meeting organizer create a meeting that uses a recurring pattern that Outlook supports.