I have an issue that is a bit more unique then the ones I've seen other people list.
Everyone is on Outlook 2010 (Exchange 2007). Several people share their calendars giving individuals reviewer permissions.
I have one user that can't view one particular user's shared calendar - they get "Could not read the Calendar" when they view it. Other users can view this shared calendar. The user that gets the error can view other people's calendars just fine. Basically it affects one user to one particular user's calendar - the rest are fine.
Based on suggestions I've found already: I have verified the permissions on the shared calendar are set (reviewer). I even removed and recreated the permissions for that problem user on the shared calendar. Have removed and rebuilt the .ost file. Have renamed the outcmd.dat file. I can go into OWA for the problem user and see the free/busy status of the shared calendar of the other user without error.
Not sure what else to try at this point.