Lock Screen Not working

[anieruddha]

Hi,

From last couple of hours, I am not able to lock my laptop screen using keyboard shortcut key.

A also tried to create custom keyboard shortcut & execute following command


dm-tool lock

IF I execute same command on command prompt, it lock screen, but if I assign same command to keyboard shortcut, it black out screen & come to desktop again, without locking screen

Ubuntu 15.10

Thanks
Aniruddha