1) the following dmesg error desappeared. The BT controller is an internal usb device.
[ 17.566030] usb 2-6: device descriptor read/64, error -110
2) M$ Bluetooth Mobile Mouse 3600 works. I removed any traces of it with bluetoothctl and I started a new setup only with GUI. Left/right clicks, movement and scroll (up/down/left/right) tested.
So #25 solved my problem. My M$ mouse 3600 now works with xenial.
I made the same as #25 and I got the following:
1) the following dmesg error desappeared. The BT controller is an internal usb device.
[ 17.566030] usb 2-6: device descriptor read/64, error -110
2) M$ Bluetooth Mobile Mouse 3600 works. I removed any traces of it with bluetoothctl and I started a new setup only with GUI. Left/right clicks, movement and scroll (up/down/ left/right) tested.
So #25 solved my problem. My M$ mouse 3600 now works with xenial.