The following instructions from Eric worked great when upgrading GhostBSD 13.2-STABLE to 14.0-STABLE

First you need to ensure to update or comment out following configuration line in /usr/local/etc/pkg.conf:

ABI = "FreeBSD:13:amd64

to

ABI = "FreeBSD:14:amd64

Eric Turgeon, [1/1/24 2:37 PM]

Eric Turgeon, [1/19/24 7:34 AM]
For those who want to test upgrade to 24.01.1 here is how you can do it.
su
bectl create 13-stable
In /etc/pkg/GhostBSD.conf do the.

url: “http://pkg.ghostbsd.org/stable/${ABI}/latest”,

url: “http://pkg.us.ghostbsd.org/stable/FreeBSD:14:amd64/latest”,
And run these commands:
env IGNORE_OSVERSION=yes pkg bootstrap -f
env ABI=FreeBSD:14:amd64 pkg-static upgrade -f
After restart the system.
if everything went fine you will need to run sudo zpool upgrade yourpoolname and you can replace url: “http://pkg.us.ghostbsd.org/stable/FreeBSD:14:amd64/latest”, by url: “http://pkg.ghostbsd.org/stable/${ABI}/latest”,.

DISCLAIMER If you are about to do the last step of the above instructions (upgrading zpool), you need to ensure the EFI bootloader (/boot/loader.efi or /boot/efi/bootx64.efi on EFI system partition) is up-to-date, otherwise the system will become unbootable. This can be noted in the section “Upgrading from Previous Releases of FreeBSD” of the release notes.

The only caveat I experienced is that the LightDM greeter kept crashing with the following error in /var/log/lightdm/seat0-greeter.log:

Gtk:ERROR:../gtk/gtkiconhelper.c:495:ensure_surface_for_gicon: assertion failed (error == NULL): Failed to load /usr/local/share/icons/Adwaita/16x16/status/image-missing.png: Unrecognized image file format (gdk-pixbuf-error-quark, 3)

A similar issue on Github gave a clue to reinstall shared-mime-info package, this resolved my issue:

pkg install -f shared-mime-info

After upgrading Mate to 1.28 some applets crashed and did not reload. Installing the following package as a dependency fixed the issue:

pkg install dconf-editor