My Outlook 2011 for Mac calendar data started disappearing for a day or longer then reappearing later for no apparent reason.  This also happened once with my Outlook 2011 for Mac task data but not at the same time as my when calendar data disappeared.  The Outlook version that I have is 14.6.0.  I have a Macbook Pro running Mavericks OS X Version 10.9.5.  Thanks in advance for your help.