When you try to use Microsoft Outlook to make a change to a recurring appointment in the Calendar of your Hotmail account or of your MSN e-mail account, you receive the following error message:
The messaging interface has returned an unknown error. If the problem persists, restart Outlook.
If you try again to make the change to the recurring appointment, you then receive the following error message:
This item is no longer valid because it has been closed.
Additionally, if you close the appointment and do not save the change, the change appears in the Calendar of your Hotmail account or of your MSN e-mail account in Outlook. However, the change does not appear in the Calendar when you use your Web browser to open your Hotmail account or your MSN e-mail account.