I am using Linux Mint 18.2 Sonja and want to connect my new **Logitech MX Master S2 mouse** without using the bluetooth-dongle, but directly with the inbuilt bluetooth module of my notebook. This works so far with my PC after running the commands: 

    ~$ sudo hciconfig hci0 sspmode 1
    ~$ sudo hciconfig hci0 down
    ~$ sudo hciconfig hci0 up

However by entering `sudo hciconfig hci0 sspmode 1` I get the following error message on my notebook:

    Can't set Simple Pairing mode on hci0: Input/output error (5)

After reading a few articles in different communities they recommended to do the following: 

    alpha@Pavilion ~ $ bluetoothctl 
    [NEW] Controller B0:35:9F:0E:4F:3D Pavilion [default]
    [NEW] Device C5:E2:3F:77:5C:3D MX Master 2S
    [NEW] Device DD:6A:F3:5A:A2:A2 MI Band 2
    [NEW] Device C5:E2:3F:77:5C:3B MX Master 2S
    [NEW] Device 00:02:3C:51:C6:12 Creative T50 Wireless
    [bluetooth]# power on
    Changing power on succeeded
    [bluetooth]# agent on
    Agent registered
    [bluetooth]# default-agent 
    Default agent request successful
    [bluetooth]# scan on
    Discovery started
    [CHG] Device C5:E2:3F:77:5C:3D RSSI: -15
    [bluetooth]# scan off
    Discovery stopped
    [CHG] Device C5:E2:3F:77:5C:3D RSSI: -4
    [bluetooth]# trust C5:E2:3F:77:5C:3D
    Changing C5:E2:3F:77:5C:3D trust succeeded
    [bluetooth]# pair C5:E2:3F:77:5C:3D
    Attempting to pair with C5:E2:3F:77:5C:3D
    [CHG] Device C5:E2:3F:77:5C:3D Connected: yes
    Failed to pair: org.bluez.Error.AuthenticationTimeout
    [CHG] Device C5:E2:3F:77:5C:3D Connected: no
    [bluetooth]# connect C5:E2:3F:77:5C:3D
    Attempting to connect to C5:E2:3F:77:5C:3D
    Failed to connect: org.bluez.Error.Failed
    [bluetooth]# version
    Version 5.37
    [bluetooth]# exit
    Agent unregistered
    [DEL] Controller B0:35:9F:0E:4F:3D Pavilion [default]
    alpha@Pavilion ~ $ 

As you can see, by trying to pair the mouse it is shortly connected and followed by the error: `Failed to pair: org.bluez.Error.AuthenticationTimeout`  
Has someone an idea?

Thanks in advance!