If you are logged in as a user using “su” or “sudo su” and attempt to use screen, you’ll get the error message “Cannot open your terminal ‘/dev/pts/0’ – please check”. This post shows how to fix this.
Solution 1
Log out of the terminal/SSH session and log back in as the user you want to run screen as instead of using su.
Solution 2
script /dev/null screen
Reference
http://serverfault.com/questions/116775/sudo-as-different-user-and-running-screen/116830
This worked for me on Debian 7.8 Wheezy.