The REAL problem source may be...

[SweatingEgg]

Hey,

Please try the following:

1. Enter into the Recovery mode (Press CMD+R during starting Mac).
2. Open MenuBar > Utilities > Terminal
3. Goto /Volumes/MYVOLUME/System/Library/LaunchDaemons (where, MYVOLUME depends on your Mac)
4. Open com.apple.bluetoothaudiod.plist from the directory with a text editor and find "com.apple.rfcomm.incoming" and change it to "com.apple.sco.incoming" like in OS X 10.9.
5. Reboot your Mac and check if your problem fixed.