X server nvidia-settings

ubuntu 16.4
driver nvidia_381
Video card gtx 1080 ti

does not work
X server nvidia-settings

sudo nvidia-settings
Failed to connect to Mir: Failed to connect to server socket
Unable to init server: Could not connect

ERROR: The control display is undefined; please run nvidia-settings --help
for usage information.

Reinstall does not help

help me, please

https://devtalk.nvidia.com/default/topic/522835/linux/if-you-have-a-problem-please-read-this-first/