Duplicate: 0009334

I can reproduce. I installed kali-root-login, then logged as root, and then the file manager can't open anymore.

Here are the logs:

Oct 10 03:35:57 kali dbus-daemon[4736]: [session uid=0 pid=4736 pidfd=5] Activating service name='org.gnome.Nautilus' requested by ':1.28' (uid=0 pid=4951 comm="/usr/bin/gnome-shell")
Oct 10 03:35:57 kali nautilus[5777]: Running as root is not supported. Consider running `nautilus admin:///` instead.
Oct 10 03:35:57 kali dbus-daemon[4736]: [session uid=0 pid=4736 pidfd=5] Activated service 'org.gnome.Nautilus' failed: Process org.gnome.Nautilus exited with status 95

Looks like it's unsupported. Maybe a change in GNOME/Nautilus.

This is a change that came with the latest GNOME release, cf. https://gitlab.gnome.org/GNOME/nautilus/-/commit/74dad718efced83dfc28a66a04fb22bd0ee955b3

Not much we can do.

Login in as root, hence running a full desktop environment as the root user, is less and less supported, generally speaking, by desktop environments.

I think it's best to stop doing that, and run as the kali user.

GNOME isn't a good desktop for running as root. I think xfce is the only one that might still fully support it, so you might want to switch to Xfce or use gnome with a regular user.
A tip that might help you run as admin in nautilus with a regular user is you can add admin:// the the directory path and it will open it as root