After updating to Mavericks, my reminders are not working?

Question

I have update my system OS to Mavericks and my old reminders are stopped working, why this happened?
how to resolve it? why my reminders stopped?

Answer 1

Back up all data.
In the iCloud preference pane, uncheck the box marked Calendars & Reminders if it's checked. You may get an alert that one or more calendars will be deleted from your computer. Confirm. The calendars won't be deleted from iCloud. Leave the preference pane open.
Quit Reminders if it's running, and also quit Calendar or iCal.
Triple-click the line below on this page to select it:  
~/Library/Calendars/Calendar Cache  
Right-click or control-click the highlighted line and select
Services ▹ Reveal
from the contextual menu.* A Finder window should open with a file named "Calendar Cache" selected.
Move the selected file to the Trash. There may be one or two other files in the same folder with names that begin in "Calendar Cache". If so, delete those files too.
If you unchecked the box in the iCloud preference pane, check it again and close the preference pane.
Launch Reminders and test.
*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination command-C. In the Finder, select
Go ▹ Go to Folder...
from the menu bar, paste into the box that opens (command-V). You won't see what you pasted because a line break is included. Press return.