You cannot open a shared Outlook folder from another user
Posted by Casey Eyring on 21 October 2011 01:14 PM
You receive an email from a user who uses Microsoft Office Outlook 2010 that invites you to view their Outlook calendar. However, the email message does not have an option that allows you to accept their invitation, only an attached XML file. In this case, you cannot open the shared Outlook folder that the user shared to you.
You attempt to open another user's outlook calendar using the "Open Shared Calendar" feature and selecting the contact from the Global Address List. That user's calendar is either blank (even though they have events in it) and/or a "Insufficent permission" alert bubble appears on your system tray.
Let's assume person A is trying to view person B's calendar.
A should now be able to open B's calendar using the following steps:
A should now be able to view B's calendar.
There is more information regarding this problem at http://support.microsoft.com/kb/2816258