FastX displays a black screen on Ubuntu

In the latest version of Ubuntu, Wayland is the default communication protocol in which FastX does not support.

Solution

Disable Wayland on Ubuntu

  1. Locate the correct configuration file for your OS. This is one of /etc/gdm3/custom.conf (Ubuntu) or /etc/gdm/custom.conf (CentOS/RHEL)
  2. Open the file with sudo/root privileges
  3. Uncomment WaylandEnable=false by deleting the # at the beginning of the line
    1. Alternatively, run the below commandsudo sed -i ‘s/^#.*WaylandEnable=.*/WaylandEnable=false/’ /etc/gdm3/custom.conf #Ubuntu
      sudo sed -i ‘s/^#.*WaylandEnable=.*/WaylandEnable=false/’ /etc/gdm/custom.conf #CentOS/RHEL
  4. Reboot