Screen session runs automatically when the machine boots, but when I try to resume it with
screen -r
It states that:There is no screen to be resumed.When you do ps aux you can see that there is a running process:
erol 2780 0.0 1.4 13612 11244 ? SNs 10:14 0:00 /usr/bin/SCREEN -dm -S myscreen
Screen checks the fifo/socket whenever it receives a SIGCHLD signal. If the socket is missing, it will be recreated. So the solution is to find the process and send it SIGCHLD.
kill -CHLD 2780$ ls /var/run/screen/S-erol/2780.myscreen
Now you can resume the session again with screen -r.