I am unable to add a new calendar and getting an error message labeled "Cannot add calendar"

Please follow the steps below to fix this issue:

1. Open Settings app on your iPhone
2. Go to "iCloud"
3. Tap on your email to drill into the account details
4. Review the Description field, and ensure it is set to iCloud

If it is already set to "iCloud", we need to reset your iCloud Calendars sync by following the steps below:

1. Go back to the previous screen (where you were on step 3 above)
2. Turn the Calendars switch OFF. Tap "Delete from my iPhone" when prompted.
3. Turn the Calendars switch back ON
4. Kill iCalendar, by following the steps below:
a) Double click the home button so iOS 7 Multitasking pops up
b) Swipe up on iCalendar to kill it.
c) Launch iCalendar again.

Now, please attempt to add a calendar. Please let me know how it goes.