$ screen -r
There is no screen to be resumed.
$ screen -dr
There is no screen to be detached.
$ screen -ls
No Sockets found in /var/run/screen/S-ilf.
$ ps aux | grep -i screen | grep -v grep
ilf 5184 0.0 0.1 4796 2060 ? Ss Feb23 0:04 SCREEN -S irc
ilf 7189 0.0 0.4 7084 4360 ? Ss Feb23 3:16 SCREEN -S main -c .screenrc_2
$ screen -r 5184
There is no screen to be resumed matching 5184.
$ screen -v
Screen version 4.00.03 (FAU) 23-Oct-06
$ apt-cache show screen | grep Version
Version: 4.0.3-0.3