Error message when accessing the CRM calendar

Error message when accessing the CRM calendar

When I click on the calendar icon in the top bar (next to the Search box), the calendar for the current month drops down.  But when I go to click on an individual date within that month, I get this error message: 

You do not have permission to view this component as corresponding module has been disabled in your profile settings (or) in Organize Tabs

Any idea why this is happening and how to fix it? 
Is there a better way to access the CRM calendar?