I installed Gnome but cannot activate gdm service. Lightdm just works well but
sudo systemctl enable gdm3
returns: ** Synchronizing state of gdm3.service with SysV service script with /lib/systemd/systemd-sysv-install. Executing: /lib/systemd/systemd-sysv-install enable gdm3 The unit files have no installation config (WantedBy=, RequiredBy=, Also=, Alias= settings in the [Install] section, and DefaultInstance= for template units). This means they are not meant to be enabled using systemctl.
Possible reasons for having this kind of units are: • A unit may be statically enabled by being symlinked from another unit's .wants/ or .requires/ directory. • A unit's purpose may be to act as a helper for some other unit which has a requirement dependency on it. • A unit may be started when needed via activation (socket, path, timer, D-Bus, udev, scripted systemctl call, ...). • In case of template units, the unit is meant to be enabled with some instance name specified. **
Have been tried re-installing, checking up config file. And set graphical.target to user's default.