GNOME on Fedora 25 and above uses Wayland instead of X11. Part of the Wayland design is to prevent graphical applications from running with root privileges.

If you are running with GNOME and have Wayland enabled (the default), the Lianja installers will run in text mode.

To run the installer in graphical mode, you will need to log in using the 'GNOME on Xorg' option in the session login screen.

Note that this also means the Lianja App Builder and the Lianja App Center cannot be run as root / with sudo when Wayland is enabled.

For more information on Wayland in GNOME on Fedora please see here Fedora 26: Common F26 bugs: Wayland issues.