Lately I have been having issues with my macbook 13in retina 2013.The bluetooth on the mac doesnt connect to any device.After trying a lot of things this is the only solution that worked for me.

sudo launchctl unload /System/Library/LaunchDaemons/
sudo launchctl load /System/Library/LaunchDaemons/

I guess this turns off the bluetooth device deamon/agent and voila bluetooth now works.