$ 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