If you see an error message saying "gconf-sanity-check-2 exited with status 256" when starting a Gnome desktop on a Linux system, it means that there is a problem with the configuration of the Gnome desktop.
This error is usually caused by a corrupted configuration file or a problem with the Gnome settings daemon (gconfd-2).
To fix this issue, you can try the following:
killall gconfd-2
This will stop the daemon and allow it to start again.
Reset the Gnome configuration: If the problem persists, you may need to reset the Gnome configuration. You can do this by deleting the ~/.gconf directory and the ~/.gconfd directory. These directories contain the Gnome configuration files and deleting them will reset the configuration to its default state.
Check for damaged configuration files: If the problem is still not fixed, it may be caused by damaged configuration files. You can try to repair the damaged configuration files by running the following command:
gconftool-2 --recursive-unset /
This will reset all the Gnome configuration values to their default state.