[Linux] Can't open display

# please check listening on port 6000. You may use command below

netstat -an | grep -F 6000

# check existing line below

tcp     0   0 0.0.0.0:6000      0.0.0.0:*              LISTEN






# if you havn't line above run command below

socat -d -d TCP-LISTEN:6000,fork,bind=0.0.0.0 UNIX-CONNECT:/tmp/.X11-unix/X0

# if you haven't socat try line below

sudo apt-get install socat