I have a Mac Pro 5,1. My Magic Mouse has been fine since installation of Yosemite, but my Magic Trackpad won't pair. In the System Preferences Trackpad pane the trackpad shows up but when I try to pair I get the message "The pairing attempt was unsuccessful. Click Continue to try again." But it just goes through the process all over again. And again. And again... Rebooted. Shut everything off. Even tried manually restarting bluetooth in Terminal: sudo kextunload -b com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport sudo kextload -b com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport Fresh alkaline batteries, trackpad is about 1 foot from the Mac Pro. Any ideas? Trackpad pairs fine with my MacBook Air. I just can't get it to pair with the Mac Pro.