I tried to pair headphones to my Ubuntu desktop and couldn’t do it because Bluetooth refused to turn on. My first instinct was to check if Bluetooth was disabled in BIOS, but this Lenovo K450 doesn’t have that option. Here’s how it was fixed:
System Settings > Bluetooth, showed Bluetooth off. Turning it on still showed “Bluetooth is disabled”.
Checking if it was software disabled checked out also:
rfkill list bluetooth
showed that it was not blocked.
Finally, I found it was disabled in the Bluetooth configuration file. To enable, edit /etc/bluetooth/main.conf and add the line:
AutoEnable=true
Ask Ubuntu Reference
Then restart Bluetooth:
sudo service bluetooth restart