I just noticed that the Bluetooth icon is missing in the tray icons and the Settings app. How can I get it back?
I figured it out!
I totally ruled this out because I didn't think it would be at all related but when I turned off my WiFi (because I moved to a wired connection) it disabled Bluetooth along with it. I enabled WiFi again and restarted and Bluetooth is back.
Please execute this command in your terminal,
sudo apt-get install switchboard-plug-bluetooth