If Bluetooth is stuck in the on or off setting, this simple procedure should cure the problem.
You may have already tried clicking in the Status bar icon or the System Preferences pane; perhaps you even did a Restart, all without effect.
The surprisingly simple answer is:
Shutdown the mac, and power on again.
Shutdown works whereas Restart doesn’t because – unlike Restart – Shutdown puts the Bluetooth power manager through a complete power cycle.
More Bluetooth problems? Drop a comment below!