Whenever I try to start a screen-session as a non-root-user I get No more PTYs. as a response. Same command in the same directory as root works properly.I tried the solution from this post but it wont change anything:$ ls /dev/pts  $ cat /proc/sys/kernel/pty/nr0$ cat /proc/sys/kernel/pty/max4096Even unmounting and remounting doesnt help:$ grep /dev/pts /proc/mountsdevpts /dev/pts devpts rw,nosuid,noexec,relatime 0 0$ umount devpts$ mount devpts /dev/pts -t devpts -o mode=620Related question of mine: Starting a minecraft server using screen doesn´t work properly
No more PTYs when starting screen as non root-user
debian;gnu screen;not root user;pty
Very likely you cannot make screen use the BSD pseudo terminals because it is compiled to use a specific style of pseudo terminal (never both).  There are two main flavors with variations:a function (such as openpty) provides the names for the master and slave devicesthe program searches through a list of master/slave pairs for an unused pairIn the latter case, you could do astrings /usr/bin/screenand find something like this: 0123456789abcdef (perhaps longer).  If you do not find that, it is compiled for Unix98 pseudo terminals.If you do find the string, it is possible that screen has to run setuid'd, e.g., to root (so that it can modify the permissions and ownership of the master/slave pairs).Since the question implies that it works running as root, it is likely to work for ordinary users after something likesudo chmod u+s /usr/bin/screen