If I open the mouse preference pane it crashes. I get the message “System Preferences quit unexpectedly.” If I turn off the mouse I can open the mouse preference pane with my trackpad but as soon as I turn on the mouse the pane crashes. I have two magic mice and they both have the same effect and both mice work on my DVR that is running Yosemite. Both computers use a BCM94360CS2 Wifi AC and Bluetooth 4.0 card. This problem just started. My mouse was moving erratically and I went to check the mouse settings. Up until now I had a trouble free installation. Back in November I had done a clean install and the pref pane was working then. Things I’ve tried: I deleted the mouse preferences Deleted System preferences Using Time Machine I replaced the mouse preference pane with a backup copy from March Using Onyx I deleted all cache, repaired permissions, rebuilt launch services etc. Has anyone else had this problem? Update My Logitech M555b Bluetooth mouse will open the mouse preference pane. When the pane is open, if I turn on the Magic Mouse it quits unexpectedly.