I’ve exclusively used Bluetooth devices to connect to my docked MacBook Pro for many, many months. It’s been a blissful period of time…one that came to a crashing halt this morning. After spending an aggravating period of time getting things working, I wanted to share with the Internet broadly (one) solution to getting both an Apple Wireless Bluetooth Keyboard and Magic Mouse (re)paired with OS X. I will note that I first ‘lost’ my Magic Mouse, and after a restart of my computer subsequently was unable to pair my Apple Wireless Bluetooth Keyboard.

Problem:

After months of blissful Bluetooth connectivity, I’ve awoken to discover that neither my Magic Mouse nor my Apple Bluetooth Keyboard are properly pairing. First my Magic Mouse failed to scroll, which led me to remove the Magic Mouse and attempt to pair it to my computer again. This attempt failed. I then rebooted my computer, and was still unable to pair my computer and Magic Mouse. After another restart, my Apple Bluetooth Keyboard was also unable to be be used as an input device with my computer. It is important to note that, while the Bluetooth Device Manager reported this failure to pair, both devices are reported as ‘connected’ under the Bluetooth icon in the OX X menu bar. Neither device, at this point, is responding to any input.

Solution:

1. Delete com.apple.Bluetooth.plist. This file is found at HD/Library/Preferences.
2. Turn off Bluetooth on your Mac. This is done by clicking the Bluetooth icon in the menu bar and selecting ‘Turn Bluetooth Off’.
3. Unplug input-based USB devices (e.g. any USB mice, keyboards, Wacom tablets, etc).
4. Shut down computer. Do *not* restart, but do a full shut down.
5. Turn off your Bluetooth devices.
6. Boot computer.
7. Turn Bluetooth on.
8. Begin pairing devices. This involves clicking: Bluetooth icon in menu bar >> Set up Bluetooth Device >>  Select Bluetooth device >> Follow on-screen instructions. In the case of your keyboard, I would suggest pressing the ‘Enter/Return’ button several times after entering the passphrase shown on your screen.

This should result in your devices being reconnected.

What May Have Provoked/Complicated My Problem:

Shortly before I had this issue with my Bluetooth devices, I updated my MagicPrefs app. This application is meant to give more complete functionality to your Magic Mouse, and to Apple’s new Magic Trackpad as well. Suspecting this might be driving my problem, I removed both applications by:

1. Quitting MagicPrefs by clicking on its icon in the menu bar and selecting ‘Quit’.
2. Drag MagicPrefs.app (found in your Applications folder) to the trash.
3. Open the Preference pane, right-click on Magic Prefs and select ‘Remove MagicPrefs Preference Pane.’ Do the same for the Magic Menu item in the Preferences pane.

I removed these applications prior to the above written solution. This may, or may not, be required to resolve the Bluetooth pairing problem; I haven’t investigated any correlation between the MagicPrefs application and my problem, but felt it valuable to note this element of my troubleshooting process.