This procedure will revert your settings in the Notifications preference pane to the defaults.
Please back up all data before continuing.
Step 1
Triple-click anywhere in the line below on this page to select it:
~/Library/Application Support/NotificationCenter
Right-click or control-click the line and select
Services ▹ Open
from the contextual menu.* A folder should open. Inside it are one or more files with long names. Move the files to the Trash.
Step 2
Open this folder in the same way:
~/Library/Preferences/ByHost
There may be one or more files with a name beginning like this:
com.apple.notificationcenterui
Move those files, and only those, to the Trash, if they exist.
Step 3
Do as in Step 2 with this folder:
~/Library/Preferences
Log out or restart the computer and empty the Trash. Recreate the settings.
*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 and paste into the box that opens by pressing command-V. You may not see what you pasted because a line break is included. Press return.
Step 4
Take this step only if you still have trouble after taking all the preceding steps.
Triple-click anywhere in the line of text below on this page to select it:
open $TMPDIR..
Copy the selected text to the Clipboard by pressing the key combination command-C.
Launch the built-in Terminal application in any one of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad and start typing the name.
Paste into the Terminal window by pressing command-V. Depending on which web browser you use, you may have to press the return key. A folder with a long, random name should open. Inside it, there should be a subfolder named "C". Drag that to the Trash.
Log out or restart the computer. Empty the Trash. Test.
