Package: x2goserver Version: 4.0.1.20-1.el7.x86_64 Package: x2goplugin-provider Version: 4.1.0.0-1.el7.x86_64 Package: x2goplugin Version: 4.1.0.0-1.el7.x86_64 All packages are from the official EPEL 7 repository. When trying to log in using the firefox plugin, the error is: Failed to connect: Permission denied. The same credentials work with the x2go client. I used the example X2Go Demo config file, only changing server=IPaddress.