Having an issue with an Exchange 2013 box (upgraded from 2007) regarding shared public/resource calendars. At random times, users will be unable to open them while others have no issues.
Errors given while problem exists:
Outlook: The connection to Microsoft exchange is unavailable.
OWA: A connection couldn't be made with the shared calendar. Remove the calendar and try to add it again, or contact its owner and ask them to share it again.
Problem will eventually resolve for a bit, but ultimately will return at random times.
Any ideas where to start with this one?