Hi Jaap, I create a new judgeHost to connect domserver. When I run submitted file to new judgehost, it gave me a message: Compiling failed with exitcode 255, compiler output: sudo: unable to stat /etc/sudoers.d/sudoers-domjudge: No such file or directory sudo: unable to resolve host acm-jugde-2016 /root/domjudge/judgehost/bin/runguard: cannot start `/root/domjudge/judgehost/judgings/acm-jugde-2016/endpoint-default/executable/cpp/run': Permission denied Try `/root/domjudge/judgehost/bin/runguard --help' for more information. Please help Lec. Huỳnh Anh Dũng ACM/ICPC SUPERVISOR FPT UNIVERSITY. http://www.fpt.edu.vn