One way to fix ”No screens found” is to create xorg.conf file which uses vesa driver in FreeBSD. If you are into tty (command prompt), run

Xorg :1 -configure

It makes a /root/xorg.conf.new file, so modify that file replacing driver line(s) as

Driver "vesa"

Use your favorite editor for editing (nano, vi, …)

When you have edited /root/xorg.conf.new file, copy that file to /etc/X11 folder.

cp /root/xorg.conf.new /etc/X11/xorg.conf

Install also xinit and twm packages

pkg install xinit twm

Reboot and see what happens

You should get desktop on, and if not, run

startx

… or

startx mate-session ## if you use mate desktop

If X does not start, comment (add # in the front of lines) other graphich drivers on boot, eg

## sysrc kld_list+=i915kms ## intel
## sysrc kld_list+=radeonkms ## amd
## sysrc kld_list+=nvidia-modeset ## nvidia
## sysrc kld_list+=nvidia ## older nvidia